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Wahid HH, Anahar FN, Isahak NH, Mohd Zoharodzi J, Mohammad Khoiri SNL, Mohamad Zainal NH, Kamarudin N, Ismail H, Mustafa Mahmud MIA. Role of Platelet Activating Factor as a Mediator of Inflammatory Diseases and Preterm Delivery. THE AMERICAN JOURNAL OF PATHOLOGY 2024; 194:862-878. [PMID: 38403163 DOI: 10.1016/j.ajpath.2024.01.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/16/2024] [Accepted: 01/31/2024] [Indexed: 02/27/2024]
Abstract
Nearly 70% of preterm deliveries occur spontaneously, and the clinical pathways involved include preterm labor and preterm premature rupture of membranes. Prediction of preterm delivery is considered crucial due to the significant effects of preterm birth on health and the economy at both the personal and community levels. Although similar inflammatory processes occur in both term and preterm delivery, the premature activation of these processes or exaggerated inflammatory response triggered by infection or sterile factors leads to preterm delivery. Platelet activating factor (PAF) is a phosphoglycerylether lipid mediator of inflammation that is implicated in infections, cancers, and various chronic diseases and disorders including cardiovascular, renal, cerebrovascular, and central nervous system diseases. In gestational tissues, PAF mediates the inflammatory pathways that stimulate the effector mechanisms of labor, including myometrial contraction, cervical dilation, and fetal membrane rupture. Women with preterm labor and preterm premature rupture of membranes have increased levels of PAF in their amniotic fluid. In mice, the intrauterine or intraperitoneal administration of carbamyl PAF activates inflammation in gestational tissues, thereby eliciting preterm delivery. This review summarizes recent research on PAF as an important inflammatory mediator in preterm delivery and in other inflammatory disorders, highlighting its potential value for prediction, intervention, and prevention of these diseases.
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Affiliation(s)
- Hanan H Wahid
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University, Pahang, Malaysia.
| | - Fatin N Anahar
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University, Pahang, Malaysia
| | - Nurul H Isahak
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University, Pahang, Malaysia
| | - Juwairiyah Mohd Zoharodzi
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University, Pahang, Malaysia
| | - Siti N L Mohammad Khoiri
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University, Pahang, Malaysia
| | - Nurul H Mohamad Zainal
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, University of Putra Malaysia, Selangor, Malaysia
| | - Norhidayah Kamarudin
- Department of Pathology, Kulliyyah of Medicine, International Islamic University, Pahang, Malaysia
| | - Hamizah Ismail
- Department of Obstetrics & Gynaecology, Kulliyyah of Medicine, International Islamic University, Pahang, Malaysia
| | - Mohammed I A Mustafa Mahmud
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University, Pahang, Malaysia
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Bruserud Ø, Mosevoll KA, Bruserud Ø, Reikvam H, Wendelbo Ø. The Regulation of Neutrophil Migration in Patients with Sepsis: The Complexity of the Molecular Mechanisms and Their Modulation in Sepsis and the Heterogeneity of Sepsis Patients. Cells 2023; 12:cells12071003. [PMID: 37048076 PMCID: PMC10093057 DOI: 10.3390/cells12071003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Common causes include gram-negative and gram-positive bacteria as well as fungi. Neutrophils are among the first cells to arrive at an infection site where they function as important effector cells of the innate immune system and as regulators of the host immune response. The regulation of neutrophil migration is therefore important both for the infection-directed host response and for the development of organ dysfunctions in sepsis. Downregulation of CXCR4/CXCL12 stimulates neutrophil migration from the bone marrow. This is followed by transmigration/extravasation across the endothelial cell barrier at the infection site; this process is directed by adhesion molecules and various chemotactic gradients created by chemotactic cytokines, lipid mediators, bacterial peptides, and peptides from damaged cells. These mechanisms of neutrophil migration are modulated by sepsis, leading to reduced neutrophil migration and even reversed migration that contributes to distant organ failure. The sepsis-induced modulation seems to differ between neutrophil subsets. Furthermore, sepsis patients should be regarded as heterogeneous because neutrophil migration will possibly be further modulated by the infecting microorganisms, antimicrobial treatment, patient age/frailty/sex, other diseases (e.g., hematological malignancies and stem cell transplantation), and the metabolic status. The present review describes molecular mechanisms involved in the regulation of neutrophil migration; how these mechanisms are altered during sepsis; and how bacteria/fungi, antimicrobial treatment, and aging/frailty/comorbidity influence the regulation of neutrophil migration.
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Affiliation(s)
- Øystein Bruserud
- Leukemia Research Group, Department of Clinical Science, University of Bergen, 5021 Bergen, Norway
- Section for Hematology, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Correspondence:
| | - Knut Anders Mosevoll
- Section for Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Section for Infectious Diseases, Department of Clinical Research, University of Bergen, 5021 Bergen, Norway
| | - Øyvind Bruserud
- Department for Anesthesiology and Intensive Care, Haukeland University Hospital, 5021 Bergen, Norway
| | - Håkon Reikvam
- Leukemia Research Group, Department of Clinical Science, University of Bergen, 5021 Bergen, Norway
- Section for Hematology, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
| | - Øystein Wendelbo
- Section for Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Faculty of Health, VID Specialized University, Ulriksdal 10, 5009 Bergen, Norway
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Liu X, Chen L, Zhang C, Dong W, Liu H, Xiao Z, Wang K, Zhang Y, Tang Y, Hong G, Lu Z, Zhao G. Ginkgolic acid promotes inflammation and macrophage apoptosis via SUMOylation and NF-κB pathways in sepsis. Front Med (Lausanne) 2023; 9:1108882. [PMID: 36743669 PMCID: PMC9892062 DOI: 10.3389/fmed.2022.1108882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 12/29/2022] [Indexed: 01/20/2023] Open
Abstract
Background Excessive inflammation and increased apoptosis of macrophages contribute to organ damage and poor prognosis of sepsis. Ginkgolic acid (GA) is a natural constituent extracted from the leaves of Ginkgo biloba, that can regulate inflammation and apoptosis. The present study aims to investigate the potential effect of GA in treating sepsis and its possible mechanisms. Materials and methods Here, a classic septic mice model and a lipopolysaccharide (LPS)-induced RAW 264.7 inflammation model were established. Cytokines in serum and culture supernatant were detected by ELISA, and the mRNA levels of them were examined by PCR. Hematoxylin and eosin (H&E) staining was performed to determine histopathological changes in liver, lung and kidney. Bacterial burden in the blood, peritoneal lavage fluids (PLFs) and organs were observed on Luria-Bertani agar medium. Flow cytometry and western blotting was used to detect apoptosis and the expression level of apoptosis related molecules, respectively. Moreover, the levels of SUMOylation were detected by western blotting. The activity of NF-κB p65 was assessed by immunofluorescence staining and western blotting. Results The result showed that GA promoted inflammatory responses, reduced bacterial clearance, aggravated organ damage, and increased mortality in septic mice. GA increased apoptosis in peritoneal macrophages (PMs) and RAW 264.7 cells. Meanwhile, GA inhibited SUMOylation and increased the nuclear translocation of NF-κB p65 as well as its phosphorylation level. Conclusion Collectively, GA promotes inflammation and macrophage apoptosis in sepsis, which may be mediated by inhibiting the SUMOylation process and increasing NF-κB p65 activity.
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Affiliation(s)
- Xinyong Liu
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China
| | - Longwang Chen
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China
| | - Chen Zhang
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China
| | - Wei Dong
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China
| | - Hongbing Liu
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China
| | - Zhong Xiao
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China
| | - Kang Wang
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China
| | - Yaolu Zhang
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China
| | - Yahui Tang
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China
| | - Guangliang Hong
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China
| | - Zhongqiu Lu
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China,*Correspondence: Zhongqiu Lu,
| | - Guangju Zhao
- Department of Emergency Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China,Wenzhou Key Laboratory of Emergency and Disaster Medicine, Wenzhou, China,Guangju Zhao,
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Pretreatment with 6-Gingerol Ameliorates Sepsis-Induced Immune Dysfunction by Regulating the Cytokine Balance and Reducing Lymphocyte Apoptosis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2021:5427153. [PMID: 35003518 PMCID: PMC8731291 DOI: 10.1155/2021/5427153] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 10/04/2021] [Accepted: 11/26/2021] [Indexed: 11/19/2022]
Abstract
Sepsis is characterized by an initial net hyperinflammatory response, followed by a period of immunosuppression, termed immunoparalysis. During this immunosuppressive phase, patients may have difficulty eradicating invading pathogens and are susceptible to life-threatening secondary hospital-acquired infections. Due to progress in antimicrobial treatment and supportive care, most patients survive early sepsis. Mortality is more frequently attributed to subsequent secondary nosocomial infections and multiorgan system failure. 6-Gingerol is the major pharmacologically active component of ginger. Although it is known to exhibit a variety of biological activities, including anti-inflammation and antioxidation, the role of 6-gingerol in sepsis-induced immune dysfunction remains elusive. Thus, we investigated whether 6-gingerol improves septic host response to infections during sepsis. 6-Gingerol-treated mice showed significantly lower mortality in polymicrobial sepsis induced by cecal ligation and puncture LPS via enhanced bacterial clearance in the peritoneum, blood, and organs (liver, spleen, and kidney) and inhibited the production of TNF-α and IL-6 in TLR2 and/or TLR4-stimulated macrophages. In addition, we demonstrated that survival improvement of secondary infection following septic insult was associated with an initial response of enhanced neutrophil numbers and function at the infection site, reduced apoptosis of immune cells, and a shift from a T helper cell type 2 (Th2) to a T helper cell type 1 (Th1) cytokine balance in the hypoinflammation phase. Our overall findings suggest that 6-gingerol potentially restores sepsis-induced immune dysfunction by shifting the balance of Th1/Th2 and by regulating apoptosis of immune cells.
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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: 27] [Impact Index Per Article: 9.0] [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.
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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.
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Sun X, Dai Y, Tan G, Liu Y, Li N. Integration Analysis of m 6A-SNPs and eQTLs Associated With Sepsis Reveals Platelet Degranulation and Staphylococcus aureus Infection are Mediated by m 6A mRNA Methylation. Front Genet 2020; 11:7. [PMID: 32174955 PMCID: PMC7054457 DOI: 10.3389/fgene.2020.00007] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 01/06/2020] [Indexed: 12/22/2022] Open
Abstract
Sepsis is a major threat with high mortality rate for critically ill patients. Response to pathogen infection by the host immune system is a key biological process involved in the onset and development of sepsis. Heterogeneous host genome variation, especially single nucleotide polymorphisms (SNPs), has long been suggested to contribute to differences in disease progression. However, the function of SNPs located in non-coding regions remains to be elucidated. Recently, m6A mRNA modification levels were revealed to differ at SNPs. As m6A is a crucial regulator of gene expression, these SNPs might control genes by changing the m6A level on mRNA. To investigate the potential role of m6A SNPs in sepsis, we integrated m6A-SNP and expression quantitative trait loci (eQTLs) data. Analysis revealed 15,720 m6A-cis-eQTLs and 381 m6A-trans-eQTLs associated with sepsis. We identified 1321 genes as locations of m6A-cis-eQTLs. These were enriched in platelet degranulation and Staphylococcus aureus infection pathways, which are vital for the pathophysiological process of sepsis. We conclude that m6A modification of mRNA plays a very important role in sepsis, with m6A-cis-eQTLs potentially having the most effect on individual variation in sepsis progression.
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Affiliation(s)
- Xuri Sun
- Department of Critical Care Medicine, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China.,Respiratory Medicine Center of Fujian Province, Quanzhou, China
| | - Yishuang Dai
- Department of Outpatient operating room, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China
| | - Guoliang Tan
- Department of Critical Care Medicine, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China.,Respiratory Medicine Center of Fujian Province, Quanzhou, China
| | - Yuqi Liu
- Department of Critical Care Medicine, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China.,Respiratory Medicine Center of Fujian Province, Quanzhou, China
| | - Neng Li
- Department of Pathogenic Biology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
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Fatemi F, Golbodagh A, Hojihosseini R, Dadkhah A, Akbarzadeh K, Dini S, Malayeri MRM. Anti-inflammatory Effects of Deuterium-Depleted Water Plus Rosa Damascena Mill. Essential Oil Via Cyclooxygenase-2 Pathway in Rats. Turk J Pharm Sci 2020; 17:99-107. [PMID: 32454767 DOI: 10.4274/tjps.galenos.2018.24381] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 11/15/2018] [Indexed: 12/29/2022]
Abstract
Objectives Natural medicine has been proposed for treating sepsis worldwide. Therefore, in this study, the effect of deuterium-depleted water (DDW) alone and adjuvant with Rosa damascena Mill. (RD) essential oils was considered through the evaluation of oxidative stress-antioxidant parameters and the expression of cyclooxygenase-2 (COX-2) inflammatory gene in liver damage caused by sepsis. Materials and Methods The rats were randomly divided into 5 groups: 1) laparotomy group; 2) cecal ligation and puncture (CLP) group; 3) DDW (15 ppm and 30 ppm doses) group; 4) DDW (15 ppm and 30 ppm doses) plus RD essential oil (100 mg/kg.bw); 5) indomethacin (2 mg/kg.bw) as a positive control. The treatments were daily administrated for 2 weeks and the CLP model was created on the day 15. Then, the animals were killed and their liver tissue was separated for histopathologic and biochemical assessment. Results Our results demonstrated that the treatment of animals with DDW and DDW plus RD essential oil was effective due to the regulation of the oxidative stress-antioxidant parameters including lipid peroxidation, glutathione (GSH), GSH s-transferases, myeloperoxidase, ferric reducing ability of plasma and inflammatory parameters such as prostaglandin E2 and COX-2. Pathological studies also showed that sepsis led to the liver tissue injuries, which can be reduced by treatments. Conclusion Sepsis caused oxidative stress in the liver tissue, but the administration of DDW and DDW plus RD essential oil can be useful to prevent and heal these injuries.
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Affiliation(s)
- Faezeh Fatemi
- Nuclear Science and Technology Research Institute, Materials and Nuclear Fuel Research School, Tehran, Iran
| | - Abbas Golbodagh
- Payame Noor University, Faculty of Sciences, Department of Biochemistry, Tehran, Iran
| | - Reza Hojihosseini
- Payame Noor University, Faculty of Sciences, Department of Biochemistry, Tehran, Iran
| | - Abolfazl Dadkhah
- Islamic Azad University, Qom Branch, Faculty of Medicine, Department of Medicine, Qom, Iran
| | - Kambiz Akbarzadeh
- Mashhad University of Medical Science, Faculty of Medicine, Mashhad, Iran
| | - Salome Dini
- Islamic Azad University, Karaj Branch, Young Researchers and Elite Club, Karaj, Iran
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Exogenous carbon monoxide inhibits neutrophil infiltration in LPS-induced sepsis by interfering with FPR1 via p38 MAPK but not GRK2. Oncotarget 2018; 7:34250-65. [PMID: 27144520 PMCID: PMC5085153 DOI: 10.18632/oncotarget.9084] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/11/2016] [Indexed: 12/29/2022] Open
Abstract
Excessive neutrophil infiltration in vital organs is life-threatening to patients who suffer from sepsis. We identified a critical role of exogenous carbon monoxide (CO) in the inhibition of neutrophil infiltration during lipopolysaccharide (LPS)-induced sepsis. CO delivered from carbon monoxide-releasing molecule 2 (CORM-2) dramatically increased the survival rate of C57BL/6 mice subjected to LPS in vivo. CORM-2 significantly suppressed neutrophil infiltration in liver and lung as well as markers of inflammatory responses. Affymetrix GeneChip array analysis revealed that the increased expression of chemoattractant receptor formyl peptide receptor 1 (FPR1) may contribute to the excessive neutrophil infiltration. The under agarose migration assay demonstrated that LPS stimulation promoted migration to the ligand of FPR1, N-Formyl-Met-Leu-Phe (fMLP) but that CORM-2 treatment inhibited this promotion. Further studies demonstrated that CORM-2 internalized FPR1 by inhibiting p38 mitogen-activated protein kinase (MAPK) but not G protein-coupled receptor kinase 2 (GRK2), which may explain the inhibitory effect of CORM-2 on LPS-stimulated neutrophils. In summary, our study demonstrates that exogenous CO inhibits sepsis-induced neutrophil infiltration by interfering with FPR1 via p38 MAPK but not GRK2.
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Daniele-Silva A, Machado RJ, Monteiro NK, Estrela AB, Santos EC, Carvalho E, Araújo Júnior RF, Melo-Silveira RF, Rocha HAO, Silva-Júnior AA, Fernandes-Pedrosa MF. Stigmurin and TsAP-2 from Tityus stigmurus scorpion venom: Assessment of structure and therapeutic potential in experimental sepsis. Toxicon 2016; 121:10-21. [DOI: 10.1016/j.toxicon.2016.08.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 07/29/2016] [Accepted: 08/23/2016] [Indexed: 02/08/2023]
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10
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Pleiotropic regulations of neutrophil receptors response to sepsis. Inflamm Res 2016; 66:197-207. [DOI: 10.1007/s00011-016-0993-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 08/24/2016] [Accepted: 09/20/2016] [Indexed: 12/21/2022] Open
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Opportunities for the development of novel therapies based on host-microbial interactions. Pharmacol Res 2016; 112:68-83. [PMID: 27107789 DOI: 10.1016/j.phrs.2016.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 12/21/2022]
Abstract
Immune responses are fundamental for protecting against most infectious agents. However, there is now much evidence to suggest that the pathogenesis and tissue damage after infection are not usually related to the direct action of the replication of microorganisms, but instead to altered immune responses triggered after the contact with the pathogen. This review article discusses several mechanisms necessary for the host to protect against microbial infection and focuses in aspects that cause altered inflammation and drive immunopathology. These basic findings can ultimately reveal pathways amenable to host-directed therapy in adjunct to antimicrobial therapy for future improved control measures for many infectious diseases. Therefore, modulating the effects of inflammatory pathways may represent a new therapy during infection outcome and disease.
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Jacob SP, Lakshmikanth CL, Chaithra VH, Kumari TRS, Chen CH, McIntyre TM, Marathe GK. Lipopolysaccharide Cross-Tolerance Delays Platelet-Activating Factor-Induced Sudden Death in Swiss Albino Mice: Involvement of Cyclooxygenase in Cross-Tolerance. PLoS One 2016; 11:e0153282. [PMID: 27064683 PMCID: PMC4827832 DOI: 10.1371/journal.pone.0153282] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 03/04/2016] [Indexed: 12/22/2022] Open
Abstract
Lipopolysaccharide (LPS) signaling through Toll-like receptor-4 (TLR-4) has been implicated in the pathogenesis of many infectious diseases. Some believe that TLR-mediated pathogenicity is due, in part, to the lipid pro-inflammatory mediator platelet-activating factor (PAF), but this has been questioned. To test the direct contribution of PAF in endotoxemia in murine models, we injected PAF intraperitoneally into Swiss albino mice in the presence and absence of LPS. PAF alone (5 μg/mouse) caused death within 15-20 min, but this could be prevented by pretreating mice with PAF-receptor (PAF-R) antagonists or PAF-acetylhydrolase (PAF-AH). A low dose of LPS (5 mg/kg body wt) did not impair PAF-induced death, whereas higher doses (10 or 20 mg/kg body wt) delayed death, probably via LPS cross-tolerance. Cross-tolerance occurred only when PAF was injected simultaneously with LPS or within 30 min of LPS injection. Tolerance does not appear to be due to an abundant soluble mediator. Histologic examination of lungs and liver and measurement of circulating TNF-α and IL-10 levels suggested that the inflammatory response is not diminished during cross-tolerance. Interestingly, aspirin, a non-specific cyclooxygenase (COX) inhibitor, partially blocked PAF-induced sudden death, whereas NS-398, a specific COX-2 inhibitor, completely protected mice from the lethal effects of PAF. Both COX inhibitors (at 20 mg/kg body wt) independently amplified the cross-tolerance exerted by higher dose of LPS, suggesting that COX-derived eicosanoids may be involved in these events. Thus, PAF does not seem to have a protective role in endotoxemia, but its effects are delayed by LPS in a COX-sensitive way. These findings are likely to shed light on basic aspects of the endotoxin cross-tolerance occurring in many disease conditions and may offer new opportunities for clinical intervention.
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Affiliation(s)
- Shancy Petsel Jacob
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysuru, 570006, Karnataka, India
| | | | | | | | - Chu-Huang Chen
- Vascular and Medicinal Research, Texas Heart Institute, Houston, Texas, 77225–0345, United States of America
| | - Thomas M. McIntyre
- Department of Cellular and Molecular Medicine (NC10), Cleveland Clinic Lerner Research Institute, 9500 Euclid Avenue, Cleveland, Ohio, 44195, United States of America
| | - Gopal Kedihitlu Marathe
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysuru, 570006, Karnataka, India
- * E-mail:
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13
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Damiani E, Ullrich SE. Understanding the connection between platelet-activating factor, a UV-induced lipid mediator of inflammation, immune suppression and skin cancer. Prog Lipid Res 2016; 63:14-27. [PMID: 27073146 DOI: 10.1016/j.plipres.2016.03.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 03/16/2016] [Accepted: 03/31/2016] [Indexed: 01/08/2023]
Abstract
Lipid mediators of inflammation play important roles in several diseases including skin cancer, the most prevalent type of cancer found in the industrialized world. Ultraviolet (UV) radiation is a complete carcinogen and is the primary cause of skin cancer. UV radiation is also a potent immunosuppressive agent, and UV-induced immunosuppression is a well-known risk factor for skin cancer induction. An essential mediator in this process is the glyercophosphocholine 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine commonly referred to as platelet-activating factor (PAF). PAF is produced by keratinocytes in response to diverse stimuli and exerts its biological effects by binding to a single specific G-protein-coupled receptor (PAF-R) expressed on a variety of cells. This review will attempt to describe how this lipid mediator is involved in transmitting the immunosuppressive signal from the skin to the immune system, starting from its production by keratinocytes, to its role in activating mast cell migration in vivo, and to the mechanisms involved that ultimately lead to immune suppression. Recent findings related to its role in regulating DNA repair and activating epigenetic mechanisms, further pinpoint the importance of this bioactive lipid, which may serve as a critical molecular mediator that links the environment (UVB radiation) to the immune system and the epigenome.
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Affiliation(s)
- Elisabetta Damiani
- Dipartimento di Scienze della Vita e dell'Ambiente, Universita' Politecnica delle Marche, Ancona, Italy
| | - Stephen E Ullrich
- Department of Immunology and The Center for Cancer Immunology Research, The University of Texas Graduate School for Biomedical Sciences at Houston, The University of Texas, MD Anderson Cancer Center, Houston, TX, USA
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Plotkowski MC, Estato V, Santos SA, da Silva MCA, Miranda AS, de Miranda PE, Pinho V, Tibiriça E, Morandi V, Teixeira MM, Vianna A, Saliba AM. Contribution of the platelet activating factor signaling pathway to cerebral microcirculatory dysfunction during experimental sepsis by ExoU producing Pseudomonas aeruginosa. Pathog Dis 2015; 73:ftv046. [PMID: 26187894 DOI: 10.1093/femspd/ftv046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2015] [Indexed: 12/18/2022] Open
Abstract
Intravital microscopy was used to assess the involvement of ExoU, a Pseudomonas aeruginosa cytotoxin with phospholipase A2 activity, in dysfunction of cerebral microcirculation during experimental pneumosepsis. Cortical vessels from mice intratracheally infected with low density of the ExoU-producing PA103 P. aeruginosa strain exhibited increased leukocyte rolling and adhesion to venule endothelium, decreased capillar density and impaired arteriolar response to vasoactive acetylcholine. These phenomena were mediated by the platelet activating factor receptor (PAFR) pathway because they were reversed in mice treated with a PAFR antagonist prior to infection. Brains from PA103-infected animals exhibited a perivascular inflammatory infiltration that was not detected in animals infected with an exoU deficient mutant or in mice treated with the PAFR antagonist and infected with the wild type bacteria. No effect on brain capillary density was detected in mice infected with the PAO1 P. aeruginosa strain, which do not produce ExoU. Finally, after PA103 infection, mice with a targeted deletion of the PAFR gene exhibited higher brain capillary density and lower leukocyte adhesion to venule endothelium, as well as lower increase of systemic inflammatory cytokines, when compared to wild-type mice. Altogether, our results establish a role for PAFR in mediating ExoU-induced cerebral microvascular failure in a murine model of sepsis.
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Affiliation(s)
- Maria Cristina Plotkowski
- Department of Microbiology, Immunology and Parasitology, State University of Rio de Janeiro, 20551-30 Rio de Janeiro, Brazil
| | - Vanessa Estato
- Laboratory of Cardiovascular Investigation, Oswaldo Cruz Institute, Rio de Janeiro, 21045-900, Brazil
| | - Sabrina Alves Santos
- Department of Microbiology, Immunology and Parasitology, State University of Rio de Janeiro, 20551-30 Rio de Janeiro, Brazil
| | | | - Aline Silva Miranda
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Pedro Elias de Miranda
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Vanessa Pinho
- Department of Morphology, Federal University of Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Eduardo Tibiriça
- Laboratory of Cardiovascular Investigation, Oswaldo Cruz Institute, Rio de Janeiro, 21045-900, Brazil
| | - Verônica Morandi
- Department of Cell Biology, State University of Rio de Janeiro, Rio de Janeiro, 20550-013, Brazil
| | - Mauro Martins Teixeira
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Albanita Vianna
- Department of Pathology, State University of Rio de Janeiro, Rio de Janeiro, 22551-030, Brazil
| | - Alessandra Mattos Saliba
- Department of Microbiology, Immunology and Parasitology, State University of Rio de Janeiro, 20551-30 Rio de Janeiro, Brazil
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15
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Saúde ACM, Ombredane AS, Silva ON, Barbosa JARG, Moreno SE, Araujo ACG, Falcão R, Silva LP, Dias SC, Franco OL. Clavanin bacterial sepsis control using a novel methacrylate nanocarrier. Int J Nanomedicine 2014; 9:5055-69. [PMID: 25382976 PMCID: PMC4222983 DOI: 10.2147/ijn.s66300] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Controlling human pathogenic bacteria is a worldwide problem due to increasing bacterial resistance. This has prompted a number of studies investigating peptides isolated from marine animals as a possible alternative for control of human pathogen infections. Clavanins are antimicrobial peptides isolated from the marine tunicate Styela clava, showing 23 amino acid residues in length, cationic properties, and also high bactericidal activity. In spite of clear benefits from the use of peptides, currently 95% of peptide properties have limited pharmaceutical applicability, such as low solubility and short half-life in the circulatory system. Here, nanobiotechnology was used to encapsulate clavanin A in order to develop nanoantibiotics against bacterial sepsis. Clavanin was nanostructured using EUDRAGIT® L 100-55 and RS 30 D solution (3:1 w:w). Atomic force, scanning electron microscopy and dynamic light scattering showed nanoparticles ranging from 120 to 372 nm in diameter, with a zeta potential of -7.16 mV and a polydispersity index of 0.123. Encapsulation rate of 98% was assessed by reversed-phase chromatography. In vitro bioassays showed that the nanostructured clavanin was partially able to control development of Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Furthermore, nanostructures did not show hemolytic activity. In vivo sepsis bioassays were performed using C57BL6 mice strain inoculated with a polymicrobial suspension. Assays led to 100% survival rate under sub-lethal sepsis assays and 40% under lethal sepsis assays in the presence of nanoformulated clavanin A until the seventh day of the experiment. Data here reported indicated that nanostructured clavanin A form shows improved antimicrobial activity and has the potential to be used to treat polymicrobial infections.
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Affiliation(s)
- Amanda C M Saúde
- Programa de Pós Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, FD, Brazil
| | - Alicia S Ombredane
- Programa de Pós Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, FD, Brazil
| | - Osmar N Silva
- Programa de Pós Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, FD, Brazil
| | - João A R G Barbosa
- Programa de Pós Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, FD, Brazil ; Laboratório de Biofísica-Departamento de Biologia Celular-IB, Universidade de Brasília - UNB, DF, Brazil
| | - Susana E Moreno
- Universidade Católica Dom Bosco - UCDB, Campo Grande, MS, Brazil
| | - Ana Claudia Guerra Araujo
- Empresa Brasileira de Pesquisa Agropecuária - EMBRAPA - Recursos Genéticos e Biotecnologia, Brasília, DF, Brazil
| | - Rosana Falcão
- Empresa Brasileira de Pesquisa Agropecuária - EMBRAPA - Recursos Genéticos e Biotecnologia, Brasília, DF, Brazil
| | - Luciano P Silva
- Empresa Brasileira de Pesquisa Agropecuária - EMBRAPA - Recursos Genéticos e Biotecnologia, Brasília, DF, Brazil
| | - Simoni C Dias
- Programa de Pós Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, FD, Brazil
| | - Octávio L Franco
- Programa de Pós Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, FD, Brazil ; Universidade Católica Dom Bosco - UCDB, Campo Grande, MS, Brazil
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16
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TLR-mediated inflammatory response to neonatal pathogens and co-infection in neonatal immune cells. Cytokine 2014; 69:211-7. [DOI: 10.1016/j.cyto.2014.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 04/30/2014] [Accepted: 06/04/2014] [Indexed: 12/22/2022]
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17
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Jin L, Batra S, Douda DN, Palaniyar N, Jeyaseelan S. CXCL1 contributes to host defense in polymicrobial sepsis via modulating T cell and neutrophil functions. THE JOURNAL OF IMMUNOLOGY 2014; 193:3549-58. [PMID: 25172493 DOI: 10.4049/jimmunol.1401138] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Severe bacterial sepsis leads to a proinflammatory condition that can manifest as septic shock, multiple organ failure, and death. Neutrophils are critical for the rapid elimination of bacteria; however, the role of neutrophil chemoattractant CXCL1 in bacterial clearance during sepsis remains elusive. To test the hypothesis that CXCL1 is critical to host defense during sepsis, we used CXCL1-deficient mice and bone marrow chimeras to demonstrate the importance of this molecule in sepsis. We demonstrate that CXCL1 plays a pivotal role in mediating host defense to polymicrobial sepsis after cecal ligation and puncture in gene-deficient mice. CXCL1 appears to be essential for restricting bacterial outgrowth and death in mice. CXCL1 derived from both hematopoietic and resident cells contributed to bacterial clearance. Moreover, CXCL1 is essential for neutrophil migration, expression of proinflammatory mediators, activation of NF-κB and MAPKs, and upregulation of adhesion molecule ICAM-1. rIL-17 rescued impaired host defenses in cxcl1(-/-) mice. CXCL1 is important for IL-17A production via Th17 differentiation. CXCL1 is essential for NADPH oxidase-mediated reactive oxygen species production and neutrophil extracellular trap formation. This study reveals a novel role for CXCL1 in neutrophil recruitment via modulating T cell function and neutrophil-related bactericidal functions. These studies suggest that modulation of CXCL1 levels in tissues and blood could reduce bacterial burden in sepsis.
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Affiliation(s)
- Liliang Jin
- Laboratory of Lung Biology, Department of Pathobiological Sciences, Center for Experimental Infectious Disease Research, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA 70803
| | - Sanjay Batra
- Laboratory of Lung Biology, Department of Pathobiological Sciences, Center for Experimental Infectious Disease Research, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA 70803
| | - David Nobuhiro Douda
- Program in Physiology and Experimental Medicine, SickKids Research Institute, Toronto, Ontario M5G 1X8, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; and
| | - Nades Palaniyar
- Program in Physiology and Experimental Medicine, SickKids Research Institute, Toronto, Ontario M5G 1X8, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; and
| | - Samithamby Jeyaseelan
- Laboratory of Lung Biology, Department of Pathobiological Sciences, Center for Experimental Infectious Disease Research, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA 70803; Division of Pulmonary and Critical Care Medicine, Department of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112
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18
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Mallet de Lima CD, da Conceição Costa J, de Oliveira Lima Santos SA, Carvalho S, de Carvalho L, Albano RM, Teixeira MM, Plotkowski MCM, Saliba AM. Central role of PAFR signalling in ExoU-induced NF-κB activation. Cell Microbiol 2014; 16:1244-54. [PMID: 24612488 DOI: 10.1111/cmi.12280] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 01/30/2014] [Accepted: 02/14/2014] [Indexed: 01/01/2023]
Abstract
ExoU is an important virulence factor in acute Pseudomonas aeruginosa infections. Here, we unveiled the mechanisms of ExoU-driven NF-κB activation by using human airway cells and mice infected with P. aeruginosa strains. Several approaches showed that PAFR was crucially implicated in the activation of the canonical NF-κB pathway. Confocal microscopy of lungs from infected mice revealed that PAFR-dependent NF-κB activation occurred mainly in respiratory epithelial cells, and reduced p65 nuclear translocation was detected in mice PAFR-/- or treated with the PAFR antagonist WEB 2086. Several evidences showed that ExoU-induced NF-κB activation regulated PAFR expression. First, ExoU increased p65 occupation of PAFR promoter, as assessed by ChIP. Second, luciferase assays in cultures transfected with different plasmid constructs revealed that ExoU promoted p65 binding to the three κB sites in PAFR promoter. Third, treatment of cell cultures with the NF-κB inhibitor Bay 11-7082, or transfection with IκBα negative-dominant, significantly decreased PAFR mRNA. Finally, reduction in PAFR expression was observed in mice treated with Bay 11-7082 or WEB 2086 prior to infection. Together, our data demonstrate that ExoU activates NF-κB by PAFR signalling, which in turns enhances PAFR expression, highlighting an important mechanism of amplification of response to this P. aeruginosa toxin.
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19
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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: 22] [Impact Index Per Article: 2.0] [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.
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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
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20
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Chacón-Salinas R, Chen L, Chávez-Blanco AD, Limón-Flores AY, Ma Y, Ullrich SE. An essential role for platelet-activating factor in activating mast cell migration following ultraviolet irradiation. J Leukoc Biol 2013; 95:139-48. [PMID: 24009177 DOI: 10.1189/jlb.0811409] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The UVB (290-320 nm) radiation in sunlight is responsible for inducing skin cancer. Exposure to UV radiation is also immunosuppressive, and the systemic immune suppression induced by UV is a well-recognized risk factor for cancer induction. As UVB radiation is absorbed within the upper layers of the skin, indirect mechanisms must play a role in activating systemic immune suppression. One prominent example is mast cell migration, which from the skin to the draining LN is an essential step in the cascade of events leading to immune suppression. What triggers mast cell migration is not entirely clear. Here, we tested the hypothesis that PAF, a lipid mediator of inflammation produced by the skin in response to UV exposure, is involved. Mast cell-deficient mice (Kit(W-sh/W-sh)) are resistant to the suppressive effect of UV radiation, and reconstituting mast cell-deficient mice with normal bone marrow-derived mast cells restores susceptibility to immunosuppression. However, when mast cells from PAFR-/- mice were used, the reconstituted mice were not susceptible to the suppressive effects of UV. Furthermore, PAFR-/- mice showed impaired UV-induced mast cell migration when compared with WT mice. Finally, injecting PAF into WT mice mimicked the effect of UV irradiation and induced mast cell migration but not in PAFR-/- mice. Our findings indicate that PAFR binding induces mast cells to migrate from the skin to the LNs, where they mediate immune suppression.
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Affiliation(s)
- Rommel Chacón-Salinas
- 1.Unit 902, The University of Texas, MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
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21
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Platelet-activating factor receptor blockade ameliorates Aggregatibacter actinomycetemcomitans-induced periodontal disease in mice. Infect Immun 2013; 81:4244-51. [PMID: 24002061 DOI: 10.1128/iai.01046-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Periodontal disease (PD) is a chronic inflammatory and alveolar bone destructive disease triggered by oral biofilm-producing microorganisms, such as Aggregatibacter actinomycetemcomitans. The levels of the phospholipid platelet-activating factor (PAF) in the saliva, gingival crevicular fluid, and periodontal tissues are significantly increased during inflammatory conditions, such as PD, but the exact mechanism that links PAF to alveolar bone resorption is not well understood. In the current study, alveolar bone resorption was induced by experimental PD through the oral inoculation of A. actinomycetemcomitans in wild-type (WT) and PAF receptor knockout (Pafr(-/-)) mice. In vitro experiments using A. actinomycetemcomitans lipopolysaccharide (LPS)-stimulated RAW 264.7 cells treated with a PAF receptor antagonist (UK74505) were also performed. The expression of lyso-PAF acetyltransferase in periodontal tissues was significantly increased 3 h after A. actinomycetemcomitans LPS injection in mice. WT and Pafr(-/-) mice that were subjected to oral inoculation of A. actinomycetemcomitans presented neutrophil accumulation and increased levels of CXCL-1 and tumor necrosis factor alpha (TNF-α) in periodontal tissues. However, Pafr(-/-) mice presented less alveolar bone loss than WT mice. The in vitro blockade of the PAF receptor impaired the resorptive activity of A. actinomycetemcomitans LPS-activated osteoclasts. In conclusion, this study shows for the first time that the blockade of PAF receptor may contribute to the progression of PD triggered by A. actinomycetemcomitans by directly affecting the differentiation and activity of osteoclasts.
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22
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Dual pili post-translational modifications synergize to mediate meningococcal adherence to platelet activating factor receptor on human airway cells. PLoS Pathog 2013; 9:e1003377. [PMID: 23696740 PMCID: PMC3656113 DOI: 10.1371/journal.ppat.1003377] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Accepted: 04/05/2013] [Indexed: 12/02/2022] Open
Abstract
Pili of pathogenic Neisseria are major virulence factors associated with adhesion, twitching motility, auto-aggregation, and DNA transformation. Pili of N. meningitidis are subject to several different post-translational modifications. Among these pilin modifications, the presence of phosphorylcholine (ChoP) and a glycan on the pilin protein are phase-variable (subject to high frequency, reversible on/off switching of expression). In this study we report the location of two ChoP modifications on the C-terminus of N. meningitidis pilin. We show that the surface accessibility of ChoP on pili is affected by phase variable changes to the structure of the pilin-linked glycan. We identify for the first time that the platelet activating factor receptor (PAFr) is a key, early event receptor for meningococcal adherence to human bronchial epithelial cells and tissue, and that synergy between the pilin-linked glycan and ChoP post-translational modifications is required for pili to optimally engage PAFr to mediate adherence to human airway cells. Neisseria meningitidis is an important human pathogen that can cause rapidly progressing, life threatening meningitis and sepsis in humans. There is no fully protective vaccine against this pathogen in current use and the key processes that dictate the transition from harmless carriage of the bacterium in the airway (the case for the vast majority of colonised hosts) to invasive disease are largely undefined. A key missing link in this organism's interaction with the human host is the identity of the receptor that is the first point of contact for the organism within the airway. In this study, we report that the receptor for this important human pathogen on airway epithelial cells is the platelet activating factor receptor (PAFr), an immunomodulatory molecule shown by others to play a role in promoting bacterial sepsis. We also show that two post-translational modifications, glycosylation and phosphorylcholine, are subject to phase-variation (high frequency, reversible switching of gene expression). They are closely associated on adjacent pilin subunits, and synergy between both are required for the efficient engagement with the PAFr. These data define a new role for these post-translational modifications in meningococcal adherence and also provide an insight into the selective pressures that underlie their phase variable expression.
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23
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Zymomonas mobilis culture protects against sepsis by modulating the inflammatory response, alleviating bacterial burden and suppressing splenocyte apoptosis. Eur J Pharm Sci 2013; 48:1-8. [DOI: 10.1016/j.ejps.2012.10.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 10/01/2012] [Accepted: 10/02/2012] [Indexed: 12/21/2022]
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24
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Liu M, Zhu H, Li J, Garcia CC, Feng W, Kirpotina LN, Hilmer J, Tavares LP, Layton AW, Quinn MT, Bothner B, Teixeira MM, Lei B. Group A Streptococcus secreted esterase hydrolyzes platelet-activating factor to impede neutrophil recruitment and facilitate innate immune evasion. PLoS Pathog 2012; 8:e1002624. [PMID: 22496650 PMCID: PMC3320582 DOI: 10.1371/journal.ppat.1002624] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 02/21/2012] [Indexed: 11/19/2022] Open
Abstract
The innate immune system is the first line of host defense against invading organisms. Thus, pathogens have developed virulence mechanisms to evade the innate immune system. Here, we report a novel means for inhibition of neutrophil recruitment by Group A Streptococcus (GAS). Deletion of the secreted esterase gene (designated sse) in M1T1 GAS strains with (MGAS5005) and without (MGAS2221) a null covS mutation enhances neutrophil ingress to infection sites in the skin of mice. In trans expression of SsE in MGAS2221 reduces neutrophil recruitment and enhances skin invasion. The sse deletion mutant of MGAS5005 (ΔsseMGAS5005) is more efficiently cleared from skin than the parent strain. SsE hydrolyzes the sn-2 ester bond of platelet-activating factor (PAF), converting biologically active PAF into inactive lyso-PAF. KM and kcat of SsE for hydrolysis of 2-thio-PAF were similar to those of the human plasma PAF acetylhydrolase. Treatment of PAF with SsE abolishes the capacity of PAF to induce activation and chemotaxis of human neutrophils. More importantly, PAF receptor-deficient mice significantly reduce neutrophil infiltration to the site of ΔsseMGAS5005 infection. These findings identify the first secreted PAF acetylhydrolase of bacterial pathogens and support a novel GAS evasion mechanism that reduces phagocyte recruitment to sites of infection by inactivating PAF, providing a new paradigm for bacterial evasion of neutrophil responses. GAS is a major human pathogen causing a variety of infections, including pharyngitis and necrotizing fasciitis. GAS pathogenesis is mediated by a large array of secreted and cell-surface virulence factors. However, the functions of many GAS virulence factors are poorly understood. Recently, we reported that the esterase secreted by GAS (SsE) is a CovRS (the control of virulence two component regulatory system)-regulated protective antigen and is critical for spreading in the skin and systemic dissemination of GAS in a mouse model of necrotizing fasciitis. This report presents three major findings regarding the function and functional mechanism of SsE: 1) SsE contributes to GAS inhibition of neutrophil recruitment; 2) SsE is a potent PAF acetylhydrolase and the first secreted bacterial PAF acetylhydrolase identified so far; and 3) the PAF receptor significantly contributes to neutrophil recruitment in skin GAS infection. These findings support a novel mechanism for evasion of the innate immune system by GAS that may be relevant to other infections.
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Affiliation(s)
- Mengyao Liu
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Hui Zhu
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
- Department of Physiology, Harbin Medical University, Harbin, People's Republic of China
| | - Jinquan Li
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Cristiana C. Garcia
- Laboratory of Immunopharmacology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Wenchao Feng
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Liliya N. Kirpotina
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Jonathan Hilmer
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, United States of America
| | - Luciana P. Tavares
- Laboratory of Immunopharmacology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Arthur W. Layton
- Montana Veterinary Diagnostic Laboratory, Bozeman, Montana, United States of America
| | - Mark T. Quinn
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, United States of America
| | - Mauro M. Teixeira
- Laboratory of Immunopharmacology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Benfang Lei
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
- * E-mail:
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25
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Christaki E, Anyfanti P, Opal SM. Immunomodulatory therapy for sepsis: an update. Expert Rev Anti Infect Ther 2012; 9:1013-33. [PMID: 22029521 DOI: 10.1586/eri.11.122] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Currently the treatment mainstay of sepsis is early and appropriate antibiotic therapy, accompanied by aggressive fluid administration, the use of vasopressors when needed and the prompt initiation of measures to support each failing organ. Activated protein C and hydrocortisone, when used accordingly can affect mortality. As the pathophysiologic events that take place during sepsis are being elucidated, new molecules that target each step of those pathways are being tested. However, a lot of those molecules affect various mediators of the sepsis cascade including inflammatory cytokines, cellular receptors, nuclear transcription factors, coagulation activators and apoptosis regulators. Over the last decade, a multitude of clinical trials and animal studies have investigated strategies that aimed to restore immune homeostasis either by reducing inflammation or by stimulating the innate and adaptive immune responses. Antibiotics, statins and other molecules with multipotent immunomodulatory actions have also been studied in the treatment of sepsis.
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Affiliation(s)
- Eirini Christaki
- Second Propedeutic Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, Hippokration Hospital, Thessaloniki, Greece.
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26
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Myrrh inhibits LPS-induced inflammatory response and protects from cecal ligation and puncture-induced sepsis. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 2012:278718. [PMID: 21826187 PMCID: PMC3151005 DOI: 10.1155/2012/278718] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 05/30/2011] [Accepted: 05/30/2011] [Indexed: 12/22/2022]
Abstract
Myrrh has been used as an antibacterial and anti-inflammatory agent. However, effect of myrrh on peritoneal macrophages and clinically relevant models of septic shock, such as cecal ligation and puncture (CLP), is not well understood. Here, we investigated the inhibitory effect and mechanism(s) of myrrh on inflammatory responses. Myrrh inhibited LPS-induced productions of inflammatory mediators such as nitric oxide, prostaglandin E2, and tumor necrosis factor-α but not of interleukin (IL)-1β and IL-6 in peritoneal macrophages. In addition, Myrrh inhibited LPS-induced activation of c-jun NH2-terminal kinase (JNK) but not of extracellular signal-regulated kinase (ERK), p38, and nuclear factor-κB. Administration of Myrrh reduced the CLP-induced mortality and bacterial counts and inhibited inflammatory mediators. Furthermore, administration of Myrrh attenuated CLP-induced liver damages, which were mainly evidenced by decreased infiltration of leukocytes and aspartate aminotransferase/alanine aminotransferase level. Taken together, these results provide the evidence for the anti-inflammatory and antibacterial potential of Myrrh in sepsis.
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Tsoupras AB, Chini M, Tsogas N, Lioni A, Tsekes G, Demopoulos CA, Lazanas MC. In vitro anti-inflammatory and anti-coagulant effects of antibiotics towards Platelet Activating Factor and thrombin. J Inflamm (Lond) 2011; 8:17. [PMID: 21736752 PMCID: PMC3162514 DOI: 10.1186/1476-9255-8-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 07/07/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sepsis is characterized as a systemic inflammatory response that results from the inability of the immune system to limit bacterial spread during an ongoing infection. In this condition the significant mediator of inflammation Platelet Activating Factor (PAF) and the coagulant factor thrombin are implicated. In animal models, treatment with PAF-antagonists or co-administration of antibiotics with recombinant-PAF-Acetylhydrolase (rPAF-AH) have exhibited promising results. In order to examine the putative anti-inflammatory and/or antithrombotic interactions between antibiotic treatment used in sepsis with PAF and/or thrombin, we studied the in vitro effects of these compounds towards PAF or/and thrombin related activities and towards PAF basic metabolic enzymes. METHODS We assessed the inhibitory effect of these drugs against PAF or thrombin induced aggregation on washed rabbit platelets (WRPs) or rabbit Platelet Reach Plasma (rPRP) by evaluating their IC50 values. We also studied their effect on Cholinephosphotransferase of PAF (PAF-CPT)/Lyso-PAF-Acetyltransferase (Lyso-PAF-AT) of rabbit leukocytes (RLs), as well as on rabbit plasma-PAF-AH, the key enzymes of both de novo/remodelling PAF biosynthesis and PAF degradation, respectively. RESULTS Several antibiotics inhibited PAF-induced platelet aggregation of both WRPs and rPRP in a concentration-depended manner, with clarithromycin, azithromycin and amikacin exhibiting the higher inhibitory effect, while when combined they synergistically inhibited PAF. Higher concentrations of all antibiotics tested were needed in order to inhibit PAF induced aggregation of rPRP, but also to inhibit thrombin induced aggregation of WRPs. Concentrations of these drugs similar to their IC50 values against PAF activity in WRPs, inhibited also in vitro PAF-CPT and Lyso-PAF-AT activities of rabbit leukocytes, while only clarithromycin and azithromycin increased rabbit plasma-PAF-AH activity. CONCLUSIONS These newly found properties of antibiotics used in sepsis suggest that apart from their general actions, these drugs may present additional beneficial anti-inflammatory and anti-coagulant effects against the onset and establishment of sepsis by inhibiting the PAF/PAF-receptor and/or the thrombin/protease-activated-receptor-1 systems, and/or by reducing PAF-levels through both PAF-biosynthesis inhibition and PAF-catabolism induction. These promising in vitro results need to be further studied and confirmed by in vivo tests, in order to optimize the efficacy of antibiotic treatment in sepsis.
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Affiliation(s)
- Alexandros B Tsoupras
- Faculty of Chemistry, National & Kapodistrian University of Athens, Panepistimioupolis of Zografou, Athens, 15771, Greece
| | - Maria Chini
- 3rd Internal Medicine Dept.-Infectious Diseases Unit, Red Cross General Hospital, Athens, Greece
| | - Nickolaos Tsogas
- 3rd Internal Medicine Dept.-Infectious Diseases Unit, Red Cross General Hospital, Athens, Greece
| | - Athina Lioni
- 3rd Internal Medicine Dept.-Infectious Diseases Unit, Red Cross General Hospital, Athens, Greece
| | - George Tsekes
- 3rd Internal Medicine Dept.-Infectious Diseases Unit, Red Cross General Hospital, Athens, Greece
| | - Constantinos A Demopoulos
- Faculty of Chemistry, National & Kapodistrian University of Athens, Panepistimioupolis of Zografou, Athens, 15771, Greece
| | - Marios C Lazanas
- 3rd Internal Medicine Dept.-Infectious Diseases Unit, Red Cross General Hospital, Athens, Greece
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Soares PMG, Lima-Junior RCP, Mota JMSC, Justino PFC, Brito GAC, Ribeiro RA, Cunha FQ, Souza MHLP. Role of platelet-activating factor in the pathogenesis of 5-fluorouracil-induced intestinal mucositis in mice. Cancer Chemother Pharmacol 2010; 68:713-20. [PMID: 21153821 DOI: 10.1007/s00280-010-1540-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 11/24/2010] [Indexed: 10/18/2022]
Abstract
PURPOSE Gastrointestinal mucositis is a common side effect of cancer chemotherapy. Platelet-activating factor (PAF) is produced during gut inflammation. There is no evidence that PAF participates in antineoplastic-induced intestinal mucositis. This study evaluated the role of PAF in 5-fluorouracil (5-FU)-induced intestinal mucositis using a pharmacological approach and PAF receptor knockout mice (PAFR(-/-)). METHODS Wild-type mice or PAFR(-/-) mice were treated with 5-FU (450 mg/kg, i.p.). Other mice were treated with saline or BN52021 (20 mg/kg, s.c.), an antagonist of the PAF receptor, once daily followed by 5-FU administration. After the third day of treatment, animals were sacrificed and tissue samples from the duodenum were removed for morphologic evaluation. In addition, myeloperoxidase activity and the cytokine concentration were measured. RESULTS 5-FU treatment decreased the duodenal villus height/crypt depth ratio, increased MPO activity, and increased the concentration of TNF-α, IL-1β and KC in comparison with saline-treated animals. In PAFR(-/-) mice and PAFR antagonist-treated mice, 5-FU-dependent intestinal damage was reduced and a decrease in duodenal villus height/crypt depth ratio was attenuated. However, the 5-FU-dependent increase in duodenum MPO activity was not affected. Without PAFR activation, 5-FU treatment did not increase the TNF-α, IL-1β and KC concentration. CONCLUSIONS In conclusion, our study establishes the role of PAFR activation in 5-FU-induced intestinal mucositis. This study implicates treatment with PAFR antagonists as novel therapeutic strategy for this condition.
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Affiliation(s)
- Pedro M G Soares
- Department of Morphology, Federal University of Ceara, Fortaleza, CE, Brazil.
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Yost CC, Weyrich AS, Zimmerman GA. The platelet activating factor (PAF) signaling cascade in systemic inflammatory responses. Biochimie 2010; 92:692-7. [PMID: 20167241 DOI: 10.1016/j.biochi.2010.02.011] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [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.
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Affiliation(s)
- Christian C Yost
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84112, USA
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Steel HC, Theron AJ, Tintinger GR, Anderson R. Posaconazole attenuates leukotriene B4 release and uptake of calcium by chemoattractant-activated human neutrophils: a potential strategy to control neutrophil-mediated inflammation. J Antimicrob Chemother 2009; 64:1008-12. [PMID: 19744985 DOI: 10.1093/jac/dkp329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES This study was designed to investigate the neutrophil-targeted anti-inflammatory potential of posaconazole (0.1-5 microM, equivalent to 0.7-3.9 mg/L) by measuring the effects of this agent on the release of leukotriene B(4) (LTB(4)) and store-operated uptake of Ca(2+) following stimulation of human neutrophils with platelet-activating factor (200 nM). METHODS LTB(4) release and uptake of Ca(2+) by the cells were measured using an enzyme immunoassay and fura-2/AM-based spectrofluorimetric procedures, respectively. RESULTS Treatment of neutrophils with posaconazole resulted in dose-related attenuation of PAF-activated release of LTB(4) and influx of Ca(2+), which attained statistical significance at 1 microM of the antimycotic. CONCLUSIONS Although primarily an antimycotic, posaconazole possesses secondary anti-inflammatory activities, which may contribute to the therapeutic efficacy of this agent in patients with sepsis.
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Affiliation(s)
- H C Steel
- Medical Research Council Unit for Inflammation and Immunity, Department of Immunology, Faculty of Health Sciences, University of Pretoria and Tshwane Academic Division of the National Health Laboratory Service, Pretoria, South Africa
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Essential role of platelet-activating factor receptor in the pathogenesis of Dengue virus infection. Proc Natl Acad Sci U S A 2009; 106:14138-43. [PMID: 19666557 DOI: 10.1073/pnas.0906467106] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Severe dengue infection in humans causes a disease characterized by thrombocytopenia, increased levels of cytokines, increased vascular permeability, hemorrhage, and shock. Treatment is supportive. Activation of platelet-activating factor (PAF) receptor (PAFR) on endothelial cells and leukocytes induces increase in vascular permeability, hypotension, and production of cytokines. We hypothesized that activation of PAFR could account for the major systemic manifestations of dengue infection. Inoculation of adult mice with an adapted strain of Dengue virus caused a systemic disease, with several features of the infection in humans. In PAFR(-/-) mice, there was decreased thrombocytopenia, hemoconcentration, decreased systemic levels of cytokines, and delay of lethality, when compared with WT infected mice. Treatment with UK-74,505, an orally active PAFR antagonist, prevented the above-mentioned manifestations, as well as hypotension and increased vascular permeability, and decreased lethality, even when started 5 days after virus inoculation. Similar results were obtained with a distinct PAFR antagonist, PCA-4246. Despite decreased disease manifestation, viral loads were similar (PAFR(-/-)) or lower (PAFR antagonist) than in WT mice. Thus, activation of PAFR plays a major role in the pathogenesis of experimental dengue infection, and its blockade prevents more severe disease manifestation after infection with no increase in systemic viral titers, suggesting that there is no interference in the ability of the murine host to deal with the infection. PAFR antagonists are disease-modifying agents in experimental dengue infection.
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Blockade of CD137 signaling counteracts polymicrobial sepsis induced by cecal ligation and puncture. Infect Immun 2009; 77:3932-8. [PMID: 19564374 DOI: 10.1128/iai.00407-09] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sepsis, a leading cause of death worldwide, involves proinflammatory responses and inefficient bacterial clearance. Previously, we have shown that CD137 (4-1BB), a member of the tumor necrosis factor receptor superfamily, plays critical roles in eradicating infective Listeria monocytogenes, a gram-positive bacterium, and that stimulation of CD137 protects mice from sepsis-induced death. In this study, we unexpectedly found that CD137 activation aggravated polymicrobial sepsis due to mixed gram-positive and gram-negative bacterial infection induced by cecal ligation and puncture (CLP). CD137-deficient (CD137(-/-)) mice showed significantly lower mortality than CD137-sufficient (CD137(+/+)) mice in the CLP model. Administration of an agonistic anti-CD137 monoclonal antibody (MAb) to CD137(+/+) mice decreased their survival in this infection model, while administration of a blocking anti-CD137 ligand MAb (TKS-1) to such mice increased their survival. CD137(-/-) mice and TKS-1-treated CD137(+/+) mice had lower levels of chemokines/proinflammatory cytokines (monocyte chemoattractant protein 1, interleukin-6 [IL-6], tumor necrosis factor alpha, IL-12) and an anti-inflammatory cytokine (IL-10), exhibited improved bacterial clearance in the peritoneum, liver, and blood, and had greater numbers of infiltrated peritoneal neutrophils and macrophages in the CLP model than control mice. Our data suggest that CD137 activation aggravates polymicrobial sepsis induced by CLP.
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Abstract
Neutrophils are key effectors of the innate immune response. Reduction of neutrophil migration to infection sites is associated with a poor outcome in sepsis. We have demonstrated a failure of neutrophil migration in lethal sepsis. Together with this failure, we observed more bacteria in both peritoneal exudates and blood, followed by a reduction in survival rate. Furthermore, neutrophils obtained from severe septic patients displayed a marked reduction in chemotactic response compared with neutrophils from healthy subjects. The mechanisms of neutrophil migration failure are not completely understood. However, it is known that they involve systemic Toll-like receptor activation by bacteria and/or their products and result in excessive levels of circulating cytokines/chemokines. These mediators acting together with LPS stimulate expression of iNOS that produces high amounts of NO, which in turn mediates the failure of neutrophil migration. NO reduced expression of CXCR2 on neutrophils and the levels of adhesion molecules on both endothelial cells and neutrophils. These events culminate in decreased endothelium-leukocyte interactions, diminished neutrophil chemotactic response, and neutrophil migration failure. Additionally, the NO effect, at least in part, is mediated by peroxynitrite. In this review, we summarize what is known regarding the mechanisms of neutrophil migration impairment in severe sepsis.
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Shio MT, Olivier M, Jancar S, Ribeiro-Dias F. Crucial cytokine interactions in nitric oxide production induced by Mycoplasma arthritidis superantigen. Microbes Infect 2008; 10:1543-51. [PMID: 18957330 DOI: 10.1016/j.micinf.2008.09.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 09/15/2008] [Accepted: 09/16/2008] [Indexed: 12/01/2022]
Abstract
Mycoplasma arthritidis causes autoimmune arthritis in rodents. It produces a superantigen (MAM) that simultaneously activates antigen presenting cells and T cells inducing nitric oxide and cytokine release. Nitric oxide is a key inducer and regulator of the immune system activation. Here, we investigated nitric oxide and cytokine production and interactions of these molecules in MAM-stimulated co-cultures of macrophages (J774A.1 cell line) with spleen lymphocytes. We found that: a) MAM-induced nitric oxide, interferon-gamma, membrane-associated tumor necrosis factor and interleukin-2 production in co-cultures of macrophages with lymphocytes from BALB/c and C3H/HePas but not from C57Bl/6 mice; b) production of nitric oxide was dependent on interferon-gamma whereas that of interferon-gamma was dependent on interleukin-2 and membrane-associated tumor necrosis factor; c) these cytokines up regulated MAM-induced nitric oxide production. Unraveling the mechanisms of cell activation induced by MAM might be helpful to design strategies to prevent immune system activation by superantigens and therefore in seeking amelioration of associated immunopathologies.
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Affiliation(s)
- Marina Tiemi Shio
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1730, Cidade Universitária, São Paulo, SP, CEP: 05508-900, Brazil
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van Zoelen MAD, Florquin S, Meijers JCM, de Beer R, de Vos AF, de Boer OJ, van der Poll T. Platelet-Activating Factor Receptor Contributes to Host Defense againstPseudomonas aeruginosaPneumonia but Is Not Essential for the Accompanying Inflammatory and Procoagulant Response. THE JOURNAL OF IMMUNOLOGY 2008; 180:3357-65. [DOI: 10.4049/jimmunol.180.5.3357] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Lu YY, Wang CP, Zhou L, Chen Y, Su SH, Feng YY, Yang YP. Synthesis of platelet-activating factor and its receptor expression in Kupffer cells in rat carbon tetrachloride-induced cirrhosis. World J Gastroenterol 2008; 14:764-70. [PMID: 18205269 PMCID: PMC2684006 DOI: 10.3748/wjg.14.764] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine the platelet-activating factor (PAF) synthesis and its receptor expression in Kupffer cells in rat carbon tetrachloride-induced cirrhosis.
METHODS: Kupffer cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were placed in serum-free medium overnight. PAF saturation binding, ET-1 saturation and competition binding were assayed. ET-1 induced PAF synthesis, mRNA expression of PAF, preproendothelin-1, endothelin A (ETA) and endothelin B (ETB) receptors were also determined.
RESULTS: A two-fold increase of PAF synthesis (1.42 ± 0.14 vs 0.66 ± 0.04 pg/&mgr;g DNA) and a 1.48-fold increase of membrane-bound PAF (1.02 ± 0.06 vs 0.69 ± 0.07 pg/&mgr;g DNA) were observed in activated Kupffer cells of cirrhotic rats. The application of ET-1 to Kupffer cells induced PAF synthesis in a concentration-dependent manner in both cirrhotic and normal rats via ETB receptor, but PAF synthesis in the activated Kupffer cells was more effective than that in the normal Kupffer cells. In activated Kupffer cells, PAF receptor expression and PAF binding capacity were markedly enhanced. Activated Kupffer cells raised the [125I]-ET-1 binding capacity, but changed neither the affinity of the receptors, nor the expression of ETA receptor.
CONCLUSION: Kupffer cells in the course of CCl4-induced cirrhosis are the main source of increased PAF. ET-1 is involved endogenously in stimulating the PAF synthesis in activated Kupffer cells via ETB receptor by paracrine. ETA receptor did not appear in activated Kupffer cells, which may exacerbate the hepatic and extrahepatic complications of cirrhosis.
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Venkatesh MP, Pham D, Kong L, Weisman LE. Prophylaxis with lactoferrin, a novel antimicrobial agent, in a neonatal rat model of coinfection. Adv Ther 2007; 24:941-54. [PMID: 18029319 DOI: 10.1007/bf02877698] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Lactoferrin has broad-spectrum antimicrobial activity, and the authors hypothesized that recombinant human lactoferrin (Talactoferrin alfa [TLF]) would reduce mortality and morbidity in a coinfection model. The MIC 50 (minimum inhibitory concentration required to inhibit the growth of 50% of organisms) of TLF against Candida albicans and Staphylococcus epidermidis was determined. Neonatal Wistar rats were infected with C albicans or S epidermidis or both, at doses of 2 x10(8) colony-forming units (CFUs) given subcutaneously. Rat pups in each group were randomly given TLF intraperitoneally at 40 mg/kg/dose or 300 mg/kg/dose, or saline in 0.2 mL, once a day for 4 d and were monitored for mortality, weight gain, and blood culture positivity. Trough serum levels of TLF were measured at 24, 48, 72, 96, and 144 h. MIC 50 of TLF was 30 microg/mL and 500 microg/mL for C albicans and S epidermidis, respectively. TLF prophylaxis significantly improved survival in the coinfection group at 40 mg/kg/dose (by 16.1%; P=.019) and at 300 mg/kg/dose (by 15.1%; P=.027) and in the S epidermidis group at a dose of 40 mg/kg/dose (by 18.6%; P=.04). Weight gain was not affected by TLF prophylaxis. Serum trough levels of TLF were 1000-fold lower than in vitro MIC 50. The authors conclude that lactoferrin prophylaxis significantly enhanced survival in coinfection and in the subgroup of S epidermidis infection (40 mg/kg/dose) through indirect mechanisms.
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McCullers JA, Iverson AR, McKeon R, Murray PJ. The platelet activating factor receptor is not required for exacerbation of bacterial pneumonia following influenza. ACTA ACUST UNITED AC 2007; 40:11-7. [PMID: 17852951 PMCID: PMC2715993 DOI: 10.1080/00365540701477568] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Pneumonia caused by Streptococcus pneumoniae is a significant cause of morbidity and mortality during influenza virus epidemics. We had previously advanced the hypothesis that interactions of pneumococcus with the receptor for platelet activating factor (PAFR) in the lung were facilitated by antecedent influenza virus infection and play a major role in the pathogenesis of bacterial superinfections. Although influenza enhanced the adherence of pneumococci to respiratory epithelial cells in vitro, chemical or antibody-mediated blockade of the PAFR did not affect adherence. In agreement with these data, mice lacking PAFR had similar bacterial loads within the lung compartment when compared to heterozygous littermates and were not protected from secondary pneumococcal pneumonia after influenza. Lack of support for this hypothesis and the observation of enhanced inflammation during secondary pneumococcal pneumonia in mice lacking PAFR may moderate enthusiasm for treatment strategies targeting the interaction of bacteria with PAFR.
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Affiliation(s)
- Jonathan A McCullers
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-2794, USA.
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Napimoga MH, Cavada BS, Alencar NMN, Mota ML, Bittencourt FS, Alves-Filho JC, Grespan R, Gonçalves RB, Clemente-Napimoga JT, de Freitas A, Parada CA, Ferreira SH, Cunha FQ. Lonchocarpus sericeus lectin decreases leukocyte migration and mechanical hypernociception by inhibiting cytokine and chemokines production. Int Immunopharmacol 2007; 7:824-35. [PMID: 17466916 DOI: 10.1016/j.intimp.2007.02.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 01/28/2007] [Accepted: 02/08/2007] [Indexed: 12/21/2022]
Abstract
In this study, we tested the potential use of a lectin from Lonchocarpus sericeus seeds (LSL), to control neutrophil migration and inflammatory hypernociception (decrease of nociceptive threshold). Pretreatment of the animals intravenously (15 min before) with LSL inhibited neutrophil migration to the peritoneal cavity in a dose-dependent fashion confirmed by an inhibition of rolling and adhesion of leukocytes by intravital microscopy. We also tested the ability of the pretreatment with LSL to inhibit neutrophil migration on immunised mice, and it was observed that a strong inhibition of neutrophil migration induced by ovoalbumin in immunized mice. Another set of experiments showed that pretreatment of the animals with LSL, inhibited the mechanical hypernociception in mice induced by the i.pl. injection of OVA in immunized mice and of carrageenan in naïve mice, but not that induced by prostaglandin E(2) (PGE(2)) or formalin. This anti-nociceptive effect correlated with an effective blockade of neutrophil influx, as assessed by the hind paw tissue myeloperoxidase levels. In addition, we measured cytokines (TNF-alpha and IL-1beta) and chemokines (MIP-1alpha [CCL3] and KC [CXCL1]) from the peritoneal exudates and i.pl. tissue. Animals treated with LSL showed inhibition of cytokines and chemokines release in a dose-dependent manner. In conclusion, we demonstrated that the inhibitory effects of LSL on neutrophil migration and mechanical inflammatory hypernocicepetion are associated with the inhibition of the production of cytokines and chemokines.
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Li RWS, Tse CM, Man RYK, Vanhoutte PM, Leung GPH. Inhibition of human equilibrative nucleoside transporters by dihydropyridine-type calcium channel antagonists. Eur J Pharmacol 2007; 568:75-82. [PMID: 17512522 DOI: 10.1016/j.ejphar.2007.04.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Revised: 04/12/2007] [Accepted: 04/17/2007] [Indexed: 10/23/2022]
Abstract
Dihydropyridine-type calcium channel antagonists, in addition to having a vasodilatory effect, are known to inhibit cellular uptake of nucleosides such as adenosine. However, the nucleoside transporter subtypes involved and the mechanism by which this occurs are not known. Therefore, we have studied the inhibitory effects of dihydropyridines on both human equilibrative nucleoside transporters, hENT-1 and hENT-2, which are the major transporters mediating nucleoside transport in most tissues. Among the dihydropyridines tested, nimodipine proved to be the most potent inhibitor of hENT-1, with an IC(50) value of 60+/-31 muM, whereas nifedipine, nicardipine, nitrendipine, and felodipine exhibited 100-fold less effective inhibitory activity. Nifedipine, nitrendipine, and nimodipine inhibited hENT-2 with IC(50) values in the micromolar range; however, nicardipine and felodipine had no significant effect on hENT-2. Removal of the 4-aryl ring or changing the nitro group at the 4-aryl ring proved not to be detrimental to the inhibitory effects of dihydropyridines on hENT-1, but resulted in a drastic decrease in their inhibitory effects on hENT-2. Kinetic studies revealed that nimodipine and nifedipine reduced V(max) of [(3)H]uridine transport without affecting K(m). The inhibitory effects of nimodipine and nifedipine could be washed out. In addition, nimodipine and nifedipine inhibited the rate of NBTGR-induced dissociation of [(3)H]NBMPR from hENT-1 cell membrane. We conclude that dihydropyridines are non-competitive inhibitors of hENT-1 and hENT-2, probably working through reversible interactions with the allosteric sites. The inhibitory potencies of dihydropyridines may be associated with the structure of the 4-aryl ring, as well as the ester groups at the C-3 and C-5 positions.
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Affiliation(s)
- Rachel W S Li
- Department of Pharmacology, The University of Hong Kong, Hong Kong
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Venkatesh MP, Pham D, Fein M, Kong L, Weisman LE. Neonatal coinfection model of coagulase-negative Staphylococcus (Staphylococcus epidermidis) and Candida albicans: fluconazole prophylaxis enhances survival and growth. Antimicrob Agents Chemother 2007; 51:1240-5. [PMID: 17261622 PMCID: PMC1855490 DOI: 10.1128/aac.01298-06] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Coagulase-negative staphylococci (CoNS) and Candida are among the most common causes of single infections and coinfections in neonates after 72 h of age. In neonates, coinfection increases the rate of mortality threefold and results in significantly greater morbidity compared to those that result from single infections. In an effort to better understand this phenomenon, we developed the first neonatal animal model of coinfection (with CoNS and Candida) and evaluated its effects on mortality and morbidity and the impact of antifungal prophylaxis with fluconazole. Neonatal Wistar rats were infected with Candida albicans and/or Staphylococcus epidermidis with doses of 2x10(8) and 2x10(6) CFU subcutaneously in different combinations and were monitored for mortality, weight gain, and bacteremia. The in vitro sensitivity of C. albicans to fluconazole was evaluated and the MIC was determined. A subset of rats in these experiments received fluconazole at 10 mg/kg of body weight/dose intraperitoneally starting 24 h before infection for 4 days, and the serum trough levels of fluconazole were measured. Coinfection in the suckling rat significantly increased the rate of mortality compared to that after infection with a single species (P<0.001) and resulted in deaths even at sublethal doses. Coinfection also impaired weight gain significantly in severely infected pups compared to that achieved after infection with a single species (P<0.001). Fluconazole prophylaxis significantly reduced mortality by 30% in the Candida group and 36% in the coinfection group and improved weight gain in this neonatal model of coinfection (P<0.001). We developed a neonatal model of coinfection with Candida and CoNS, observed significantly greater mortality and morbidity with coinfection, and found that fluconazole prophylaxis significantly reduced the rates of both mortality and morbidity. Further research on neonatal coinfection is urgently needed to improve clinical outcomes.
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Affiliation(s)
- Mohan Pammi Venkatesh
- Baylor College of Medicine and Texas Children's Hospital, Fannin, Houston, TX 77030, USA.
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