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Bodilly L, Williamson L, Howell K, Alder MN, Kaplan JM. OBESE MICE WITH PNEUMONIA HAVE HYPERLEPTINEMIA AND INCREASED PULMONARY SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 ACTIVATION. Shock 2023; 59:409-416. [PMID: 36597767 PMCID: PMC9991986 DOI: 10.1097/shk.0000000000002050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
ABSTRACT Obesity is an ongoing epidemic that influences pathobiology in numerous disease states. Obesity is associated with increased plasma leptin levels, a hormone that activates the signal transducer and activator of transcription 3 (STAT3) pathway. Pneumonia is a significant cause of morbidity and mortality. During pneumonia, inflammatory pathways including STAT3 are activated. Outcomes in obese patients with pneumonia are mixed, with some studies showing obesity increases harm and others showing benefit. It is unclear whether obesity alters STAT3 activation during bacterial pneumonia and how this might impact outcomes from pneumonia. We used a murine model of obesity and pneumonia challenge with Pseudomonas aeruginosa in obese and nonobese mice to investigate the effect of obesity on STAT3 activation. We found obese mice with bacterial pneumonia had increased mortality compared with nonobese mice. Inflammatory markers, IL-6 and TNF-α, and lung neutrophil infiltration were elevated at 6 h after pneumonia in both nonobese and obese mice. Obese mice had greater lung injury compared with nonobese mice at 6 h after pneumonia. Leptin and insulin levels were higher in obese mice compared with nonobese mice, and obese mice with pneumonia had higher pulmonary STAT3 activation compared with nonobese mice.
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Affiliation(s)
- Lauren Bodilly
- Department of Pediatrics, University of Iowa, Iowa City, IA
| | - Lauren Williamson
- Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Kendra Howell
- Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
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Reyne N, McCarron A, Cmielewski P, Parsons D, Donnelley M. To bead or not to bead: A review of Pseudomonas aeruginosa lung infection models for cystic fibrosis. Front Physiol 2023; 14:1104856. [PMID: 36824474 PMCID: PMC9942929 DOI: 10.3389/fphys.2023.1104856] [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: 11/22/2022] [Accepted: 01/25/2023] [Indexed: 02/10/2023] Open
Abstract
Cystic fibrosis (CF) lung disease is characterised by recurring bacterial infections resulting in inflammation, lung damage and ultimately respiratory failure. Pseudomonas aeruginosa is considered one of the most important lung pathogens in those with cystic fibrosis. While multiple cystic fibrosis animal models have been developed, many fail to mirror the cystic fibrosis lung disease of humans, including the colonisation by opportunistic environmental pathogens. Delivering bacteria to the lungs of animals in different forms is a way to model cystic fibrosis bacterial lung infections and disease. This review presents an overview of previous models, and factors to consider when generating a new P. aeruginosa lung infection model. The future development and application of lung infection models that more accurately reflect human cystic fibrosis lung disease has the potential to assist in understanding the pathophysiology of cystic fibrosis lung disease and for developing treatments.
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Affiliation(s)
- Nicole Reyne
- Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia,Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia,Respiratory and Sleep Medicine, Women’s and Children’s Hospital, North Adelaide, SA, Australia,*Correspondence: Nicole Reyne,
| | - Alexandra McCarron
- Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia,Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia,Respiratory and Sleep Medicine, Women’s and Children’s Hospital, North Adelaide, SA, Australia
| | - Patricia Cmielewski
- Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia,Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia,Respiratory and Sleep Medicine, Women’s and Children’s Hospital, North Adelaide, SA, Australia
| | - David Parsons
- Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia,Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia,Respiratory and Sleep Medicine, Women’s and Children’s Hospital, North Adelaide, SA, Australia
| | - Martin Donnelley
- Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia,Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia,Respiratory and Sleep Medicine, Women’s and Children’s Hospital, North Adelaide, SA, Australia
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Sabra W, Wang W, Goepfert C, Zeng AP. Food-web and metabolic interactions of the lung inhabitants Streptococcus pneumoniae and Pseudomonas aeruginosa. Environ Microbiol 2022; 24:4885-4898. [PMID: 35706134 DOI: 10.1111/1462-2920.16105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 06/03/2022] [Accepted: 06/13/2022] [Indexed: 11/29/2022]
Abstract
Bacteria that successfully adapt to different substrates and environmental niches within the lung and overcome the immune defence can cause serious lung infections. Such infections are generally complex, and recognised as polymicrobial in nature. Both Pseudomonas aeruginosa and Streptococcus pneumoniae can cause chronic lung infections and were both detected in cystic fibrosis (CF) lung at different stages. In this study, single and dual species cultures of Pseudomonas aeruginosa and Streptococcus pneumoniae were studied under well controlled planktonic growth conditions. Under pH-controlled conditions, both species apparently benefited from the presence of the other. In co-culture with P. aeruginosa, S. pneumoniae grew efficiently under aerobic conditions, whereas in pure S. pneumoniae culture, growth inhibition occurred in bioreactors with dissolved oxygen concentrations above the microaerobic range. Lactic acid and acetoin that are produced by S. pneumoniae was efficiently utilised by P. aeruginosa. In pH-uncontrolled co-cultures, the low pH triggered by S. pneumoniae assimilation of glucose and lactic acid production negatively affected the growth of both strains. Nevertheless, ammonia production improved significantly, and P. aeruginosa growth dominated at later growth stages. This study revealed unreported metabolic interactions of two important pathogenic microorganisms and shed new lights into pathophysiology of bacterial lung infection. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Wael Sabra
- Faculty of life science, Rheine-Waal University of applied sciences, Marie-Curie-Straße 1, Kleve.,Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestrasse 15, Hamburg, Germany
| | - Wei Wang
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestrasse 15, Hamburg, Germany
| | - Christiane Goepfert
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestrasse 15, Hamburg, Germany
| | - An-Ping Zeng
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestrasse 15, Hamburg, Germany.,Beijing Advanced Innovation Center for Soft Matter Science and Engineering
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Sundaresan V, Do H, Shrout JD, Bohn PW. Electrochemical and spectroelectrochemical characterization of bacteria and bacterial systems. Analyst 2021; 147:22-34. [PMID: 34874024 PMCID: PMC8791413 DOI: 10.1039/d1an01954f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Microbes, such as bacteria, can be described, at one level, as small, self-sustaining chemical factories. Based on the species, strain, and even the environment, bacteria can be useful, neutral or pathogenic to human life, so it is increasingly important that we be able to characterize them at the molecular level with chemical specificity and spatial and temporal resolution in order to understand their behavior. Bacterial metabolism involves a large number of internal and external electron transfer processes, so it is logical that electrochemical techniques have been employed to investigate these bacterial metabolites. In this mini-review, we focus on electrochemical and spectroelectrochemical methods that have been developed and used specifically to chemically characterize bacteria and their behavior. First, we discuss the latest mechanistic insights and current understanding of microbial electron transfer, including both direct and mediated electron transfer. Second, we summarize progress on approaches to spatiotemporal characterization of secreted factors, including both metabolites and signaling molecules, which can be used to discern how natural or external factors can alter metabolic states of bacterial cells and change either their individual or collective behavior. Finally, we address in situ methods of single-cell characterization, which can uncover how heterogeneity in cell behavior is reflected in the behavior and properties of collections of bacteria, e.g. bacterial communities. Recent advances in (spectro)electrochemical characterization of bacteria have yielded important new insights both at the ensemble and the single-entity levels, which are furthering our understanding of bacterial behavior. These insights, in turn, promise to benefit applications ranging from biosensors to the use of bacteria in bacteria-based bioenergy generation and storage.
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Affiliation(s)
- Vignesh Sundaresan
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
| | - Hyein Do
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Joshua D Shrout
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556, USA
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Paul W Bohn
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
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Watanabe E, Akamatsu T, Ohmori M, Kato M, Takeuchi N, Ishiwada N, Nishimura R, Hishiki H, Fujimura L, Ito C, Hatano M. Recombinant thrombomodulin attenuates hyper-inflammation and glycocalyx damage in a murine model of Streptococcus pneumoniae-induced sepsis. Cytokine 2021; 149:155723. [PMID: 34662822 DOI: 10.1016/j.cyto.2021.155723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 09/20/2021] [Indexed: 11/03/2022]
Abstract
PURPOSE The anticoagulant agent recombinant thrombomodulin (rTM) activates protein C to prevent excessive coagulation and also possibly regulates hyper-inflammation via neutralization of high-mobility-group B1 (HMG-B1). The glycocalyx layer in endothelial cells also plays a pivotal role in preventing septic shock-associated hyperpermeability. The present study examined the effect of rTM in a murine model of Streptococcus pneumoniae-induced sepsis. METHODS Male C57BL/6N mice were injected intratracheally via midline cervical incision with 2 × 107 CFU of S. pneumoniae (capsular subtype 19A). Control mice were sham-treated identically but injected with saline. rTM (10 mg/kg) was injected intraperitoneally 3 h after septic insult. Blood concentrations of soluble inflammatory mediators (interleukin [IL]-1β, IL-6, IL-10, and tumor necrosis factor [TNF]-α) were determined using a microarray immunoassay. Serum concentrations of HMG-B1 and syndecan-1, as a parameter of glycocalyx damage, were determined by enzyme-linked immunosorbent assay. The glycocalyx was also evaluated with electron microscopy. The lungs were removed, and digested to cells, which were then stained with a mixture of fluorophore-conjugated antibodies. Anti-mouse primary antibodies included PE-Cy7-conjugated anti-CD31, AlexaFluor 700-conjugated anti-CD45, PerCP-Cy5.5-conjugated anti-CD326, APC-conjugated anti-TNF-α, PE-conjugated anti-IL-6, and PE-conjugated anti-IL-10. A total of 1 × 106 cells per sample were analyzed, and 2 × 105 events were recorded by flow cytometry, and parameters were compared with/without rTM treatment. RESULTS The blood concentration of TNF-α was significantly reduced 24 h after intratracheal injection in S. pneumoniae-challenged mice treated with rTM (P = 0.016). Levels of IL-10 in the lung endothelium of rTM-treated S. pneumoniae-challenged mice increased significantly 12 h after intratracheal injection (P = 0.03). Intriguingly, serum HMGB-1 and syndecan-1 levels decreased significantly (P = 0.010 and 0.015, respectively) in rTM-treated mice 24 h after intratracheal injection of S. pneumoniae. Electron microscopy indicated that rTM treatment preserved the morphology of the glycocalyx layer in septic mice. CONCLUSIONS These data suggest that rTM modulates local inflammation in the lung endothelium, thus diminishing systemic inflammation, i.e., hypercytokinemia. Furthermore, rTM treatment reduced serum syndecan-1 levels, thus preventing glycocalyx damage. The use of rTM to treat sepsis caused by bacterial pneumonia could therefore help prevent both excessive inflammation and glycocalyx injury in the lung endothelium.
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Affiliation(s)
- Eizo Watanabe
- Department of General Medical Science, Chiba University Graduate School of Medicine, Japan; Department of Emergency and Critical Care Medicine, Graduate School of Medicine, Chiba University, Japan.
| | | | | | - Mayu Kato
- Department of Emergency and Critical Care Medicine, Graduate School of Medicine, Chiba University, Japan
| | - Noriko Takeuchi
- Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, Japan
| | - Naruhiko Ishiwada
- Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, Japan
| | - Rintaro Nishimura
- Departments of Respirology, Graduate School of Medicine, Chiba University, Japan
| | - Haruka Hishiki
- Departments of Pediatrics, Graduate School of Medicine, Chiba University, Japan
| | | | - Chizuru Ito
- Department of Functional Anatomy, Reproductive Biology and Medicine, Graduate School of Medicine, Chiba University, Japan
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Regulatory Roles of Human Surfactant Protein B Variants on Genetic Susceptibility to Pseudomonas Aeruginosa Pneumonia-Induced Sepsis. Shock 2021; 54:507-519. [PMID: 31851120 DOI: 10.1097/shk.0000000000001494] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Surfactant protein B (SP-B) is essential for life and plays critical roles in host defense and lowering alveolar surface tension. A single-nucleotide polymorphism (SNP rs1130866) of human SP-B (hSP-B) alters the N-linked glycosylation, thus presumably affecting SP-B function. This study has investigated the regulatory roles of hSP-B genetic variants on lung injury in pneumonia-induced sepsis. METHODS Wild-type (WT) FVB/NJ and humanized transgenic SP-B-T and SP-B-C mice (expressing either hSP-B C or T allele without mouse SP-B gene) were infected intratracheally with 50 μL (4 × 10 colony-forming units [CFUs]/mouse) Pseudomonas aeruginosa Xen5 or saline, and then killed 24 or 48 h after infection. Bacterial dynamic growths were monitored from 0 to 48 h postinfection by in vivo imaging. Histopathological, cellular, and molecular changes of lung tissues and bronchoalveolar lavage fluid (BALF) were analyzed. Surface tension of surfactants was determined with constrained drop surfactometry. RESULTS SP-B-C mice showed higher bioluminescence and CFUs, increased inflammation and mortality, the higher score of lung injury, and reduced numbers of lamellar bodies in type II cells compared with SP-B-T or WT (P < 0.05). Minimum surface tension increased dramatically in infected mice (P < 0.01) with the order of SP-B-C > SP-B-T > WT. Levels of multiple cytokines in the lung of infected SP-B-C were higher than those of SP-B-T and WT (P < 0.01). Furthermore, compared with SP-B-T or WT, SP-B-C exhibited lower SP-B, higher NF-κB and NLRP3 inflammasome activation, and higher activated caspase-3. CONCLUSIONS hSP-B variants differentially regulate susceptibility through modulating the surface activity of surfactant, cell death, and inflammatory signaling in sepsis.
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Chronic Alcohol Ingestion Worsens Survival and Alters Gut Epithelial Apoptosis and CD8+ T Cell Function After Pseudomonas Aeruginosa Pneumonia-Induced Sepsis. Shock 2020; 51:453-463. [PMID: 29664837 DOI: 10.1097/shk.0000000000001163] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Mortality is higher in septic patients with a history of alcohol use disorder than in septic patients without a history of chronic alcohol usage. We have previously described a model of chronic alcohol ingestion followed by sepsis from cecal ligation and puncture in which alcohol-fed septic mice have higher mortality than water-fed septic mice, associated with altered gut integrity and increased production of TNF and IFNγ by splenic CD4 T cells without alterations in CD8 T cell function. The purpose of this study was to determine whether this represents a common host response to the combination of alcohol and sepsis by creating a new model in which mice with chronic alcohol ingestion were subjected to a different model of sepsis. C57Bl/6 mice were randomized to receive either alcohol or water for 12 weeks and then subjected to Pseudomonas aeruginosa pneumonia. Mice were sacrificed either 24 hours after the onset of sepsis or followed for survival. Alcohol-fed septic mice had significantly higher 7-day mortality than water-fed septic mice (96% vs 58%). This was associated with a 5-fold increase in intestinal apoptosis in alcohol-fed septic animals, accompanied by an increase in the pro-apoptotic protein Bax. Serum IL-6 levels were higher and IL-2 levels were lower in alcohol-fed septic mice. In contrast, CD8 T cell frequency was lower in alcohol-fed mice than water-fed septic mice, associated with increased production of IFNγ and TNF in stimulated splenocytes. No significant differences were noted in CD4 T cells, lung injury or bacteremia. Mice with chronic alcohol ingestion thus have increased mortality regardless of their septic insult, associated with changes in both the gut and the immune system.
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Complement depletion and Coombs positivity in pneumococcal hemolytic uremic syndrome (pnHUS). Case series and plea to revisit an old pathogenetic concept. Int J Med Microbiol 2018; 308:1096-1104. [PMID: 30177469 DOI: 10.1016/j.ijmm.2018.08.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/21/2018] [Accepted: 08/27/2018] [Indexed: 12/27/2022] Open
Abstract
Hemolytic uremic syndrome is a rare complication of invasive pneumococcal infection (pnHUS). Its pathogenesis is poorly understood, and treatment remains controversial. The emerging role of complement in various forms of HUS warrants a new look at this "old" disease. We performed a retrospective analysis of clinical and laboratory features of three sequential cases of pnHUS since 2008 associated with pneumonia/pleural empyema, two due to Streptococcus pneumoniae serotype 19 A. Profound depletion of complement C3 (and less of C4) was observed in two patients. One patient was Coombs test positive. Her red blood cells (RBCs) strongly agglutinated with blood group compatible donor serum at 0 °C, but not at 37 °C. All three patients were treated with hemodialysis, concentrated RBCs, and platelets. Patient 2 received frozen plasma for hepatic failure with coagulation factor depletion. Intravenous immunoglobulin infusion, intended to neutralize pneumococcal neuraminidase in patient 3, was associated with rapid normalization of platelets and cessation of hemolysis. Two patients recovered without sequelae or disease recurrence. Patient 2 died within 2½ days of admission due to complicating Pseudomonas aeruginosa sepsis and multiorgan failure. Our observations suggest that pnHUS can be associated with dramatic, transient complement consumption early in the course of the disease, probably via the alternative pathway. A critical review of the literature and the reported cases argue against the postulated pathological role of preformed antibodies against the neuraminidase-exposed Thomsen-Friedenreich neoantigen (T antigen) in pnHUS. The improved understanding of complement regulation and bacterial strategies of complement evasion allows to propose a testable, new pathogenetic model of pnHUS. This model shifts emphasis from the action of natural anti-T antibodies toward impaired Complement Factor H (CFH) binding and function on desialylated membranes. Removal of neuraminic acid residues converts (protected) self to non-self surfaces that supports membrane attack complex (MAC) assembly. Complement activation is potentially exacerbated by decreased CFH availability following tight CFH binding to pneumococcal evasion proteins and/or by the presence of genetic variants of complement regulator proteins. Detailed clinical and experimental investigations are warranted to better understand the role of unregulated complement activation in pnHUS. Instead of avoidance of plasma, a new, integrated model is evolving, which may include short-term therapeutic complement blockade, particularly where genetic or functional APC dysregulation is suspected, in addition to bacterial elimination and, potentially, neuraminidase neutralization.
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Stravinskas Durigon T, MacKenzie B, Carneiro Oliveira-Junior M, Santos-Dias A, De Angelis K, Malfitano C, Kelly da Palma R, Moreno Guerra J, Damaceno-Rodrigues NR, Garcia Caldini E, de Almeida FM, Aquino-Santos HC, Rigonato-Oliveira NC, Leal de Oliveira DB, Aimbire F, Ligeiro de Oliveira AP, Franco de Oliveira LV, Durigon EL, Hiemstra PS, Vieira RP. Aerobic Exercise Protects from Pseudomonas aeruginosa-Induced Pneumonia in Elderly Mice. J Innate Immun 2018; 10:279-290. [PMID: 29843140 DOI: 10.1159/000488953] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/04/2018] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Pseudomonas aeruginosa (PS) infection results in severe morbidity and mortality, especially in immune-deficient populations. Aerobic exercise (AE) modulates the immune system, but its effects on the outcomes of pulmonary PS infection in elderly mice are unknown. METHODS BALB/c mice (24 weeks old) were randomized to sedentary, exercise (EX), PS, and PS + EX groups for the acute experimental setting, and PS and PS + EX groups for the chronic setting. Low-intensity AE was performed for 5 weeks, 60 min/day; 24 h after the final AE session, mice were inoculated with 5 × 104 colony-forming units (CFU) of PS, and 24 h and 14 days after PS inoculation, mice were studied. RESULTS AE inhibited PS colonization (p < 0.001) and lung inflammation (total cells, neutrophils, lymphocytes [p < 0.01] in bronchoalveolar lavage [BAL]), with significant differences in BAL levels of IL-1β (p < 0.001), IL-6 (p < 0.01), CXCL1 (p < 0.001), and TNF-α (p < 0.001), as well as parenchymal neutrophils (p < 0.001). AE increased BAL levels of IL-10 and parenchymal (p < 0.001) and epithelial (p < 0.001) IL-10 expression, while epithelial (p < 0.001) and parenchymal (p < 0.001) NF-κB expression was decreased. AE diminished pulmonary lipid peroxidation (p < 0.001) and increased glutathione peroxidase (p < 0.01). Pre-incubation of BEAS-2B with IL-10 inhibited PS-induced epithelial cell expression of TNF-α (p < 0.05), CD40 (p < 0.01), and dichlorodihydrofluorescein diacetate (p < 0.05). CONCLUSIONS AE inhibits PS-induced lung inflammation and bacterial colonization in elderly mice, involving IL-10/NF-κB, and redox signaling.
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Affiliation(s)
- Thomas Stravinskas Durigon
- Brazilian Institute of Teaching and Research in Pulmonary and Exercise Immunology (IBEPIPE), São José dos Campos, Brazil
| | - BreAnne MacKenzie
- Brazilian Institute of Teaching and Research in Pulmonary and Exercise Immunology (IBEPIPE), São José dos Campos, Brazil
| | | | - Alana Santos-Dias
- Brazilian Institute of Teaching and Research in Pulmonary and Exercise Immunology (IBEPIPE), São José dos Campos, Brazil
| | - Kátia De Angelis
- Department of Physiology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Christiano Malfitano
- Science Department of Health, Federal University of Lavras (UFLA), Lavras, Brazil
| | - Renata Kelly da Palma
- Department of Health Sciences, Nove de Julho University (UNINOVE), São Paulo, Brazil
| | - Juliana Moreno Guerra
- Brazilian Institute of Teaching and Research in Pulmonary and Exercise Immunology (IBEPIPE), São José dos Campos, Brazil
| | | | - Elia Garcia Caldini
- Department of Pathology (LIM 59), University of São Paulo, São Paulo, Brazil
| | - Francine Maria de Almeida
- Brazilian Institute of Teaching and Research in Pulmonary and Exercise Immunology (IBEPIPE), São José dos Campos, Brazil
| | | | | | - Danielle Bruna Leal de Oliveira
- Laboratory of Virology, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Flavio Aimbire
- Institute of Science and Technology, Federal University of São Paulo (UNIFESP), São José dos Campos, Brazil
| | | | | | - Edison Luiz Durigon
- Laboratory of Virology, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Pieter S Hiemstra
- Department of Pulmonology, Leiden University Medical Center, Leiden, the Netherlands
| | - Rodolfo P Vieira
- Brazilian Institute of Teaching and Research in Pulmonary and Exercise Immunology (IBEPIPE), São José dos Campos, Brazil.,Postgraduation Program in Bioengineering, Universidade Brasil, São Paulo, Brazil.,Postgraduation Program in Sciences of Human Movement and Rehabilitation, Federal University of São Paulo (UNIFESP), Santos, Brazil
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Abstract
Intestinal barrier dysfunction is thought to contribute to the development of multiple organ dysfunction syndrome in sepsis. Although there are similarities in clinical course following sepsis, there are significant differences in the host response depending on the initiating organism and time course of the disease, and pathways of gut injury vary widely in different preclinical models of sepsis. The purpose of this study was to determine whether the timecourse and mechanisms of intestinal barrier dysfunction are similar in disparate mouse models of sepsis with similar mortalities. FVB/N mice were randomized to receive cecal ligation and puncture (CLP) or sham laparotomy, and permeability was measured to fluoresceinisothiocyanate conjugated-dextran (FD-4) six to 48 h later. Intestinal permeability was elevated following CLP at all timepoints measured, peaking at 6 to 12 h. Tight junction proteins claudin 1, 2, 3, 4, 5, 7, 8, 13, and 15, Junctional Adhesion Molecule-A (JAM-A), occludin, and ZO-1 were than assayed by Western blot, real-time polymerase chain reaction, and immunohistochemistry 12 h after CLP to determine potential mechanisms underlying increases in intestinal permeability. Claudin 2 and JAM-A were increased by sepsis, whereas claudin-5 and occludin were decreased by sepsis. All other tight junction proteins were unchanged. A further timecourse experiment demonstrated that alterations in claudin-2 and occludin were detectable as early as 1 h after the onset of sepsis. Similar experiments were then performed in a different group of mice subjected to Pseudomonas aeruginosa pneumonia. Mice with pneumonia had an increase in intestinal permeability similar in timecourse and magnitude to that seen in CLP. Similar changes in tight junction proteins were seen in both models of sepsis although mice subjected to pneumonia also had a marked decrease in ZO-1 not seen in CLP. These results indicate that two disparate, clinically relevant models of sepsis induce a significant increase in intestinal permeability mediated through a common pathway involving alterations in claudin 2, claudin 5, JAM-A, and occludin although model-specific differences in ZO-1 were also identified.
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Bielen K, 's Jongers B, Malhotra-Kumar S, Jorens PG, Goossens H, Kumar-Singh S. Animal models of hospital-acquired pneumonia: current practices and future perspectives. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:132. [PMID: 28462212 DOI: 10.21037/atm.2017.03.72] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Lower respiratory tract infections are amongst the leading causes of mortality and morbidity worldwide. Especially in hospital settings and more particularly in critically ill ventilated patients, nosocomial pneumonia is one of the most serious infectious complications frequently caused by opportunistic pathogens. Pseudomonas aeruginosa is one of the most important causes of ventilator-associated pneumonia as well as the major cause of chronic pneumonia in cystic fibrosis patients. Animal models of pneumonia allow us to investigate distinct types of pneumonia at various disease stages, studies that are not possible in patients. Different animal models of pneumonia such as one-hit acute pneumonia models, ventilator-associated pneumonia models and biofilm pneumonia models associated with cystic fibrosis have been extensively studied and have considerably aided our understanding of disease pathogenesis and testing and developing new treatment strategies. The present review aims to guide investigators in choosing appropriate animal pneumonia models by describing and comparing the relevant characteristics of each model using P. aeruginosa as a model etiology for hospital-acquired pneumonia. Key to establishing and studying these animal models of infection are well-defined end-points that allow precise monitoring and characterization of disease development that could ultimately aid in translating these findings to patient populations in order to guide therapy. In this respect, and discussed here, is the development of humanized animal models of bacterial pneumonia that could offer unique advantages to study bacterial virulence factor expression and host cytokine production for translational purposes.
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Affiliation(s)
- Kenny Bielen
- Molecular Pathology Group, Faculty of Medicine and Health Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.,Laboratory of Medical Microbiology - Vaccine and Infectious Disease Institute, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Bart 's Jongers
- Molecular Pathology Group, Faculty of Medicine and Health Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.,Laboratory of Medical Microbiology - Vaccine and Infectious Disease Institute, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Surbhi Malhotra-Kumar
- Laboratory of Medical Microbiology - Vaccine and Infectious Disease Institute, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Philippe G Jorens
- Department of Critical Care Medicine, Antwerp University Hospital and University of Antwerp, LEMP, Wilrijkstraat 10, B-2650 Edegem, Belgium
| | - Herman Goossens
- Laboratory of Medical Microbiology - Vaccine and Infectious Disease Institute, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Samir Kumar-Singh
- Molecular Pathology Group, Faculty of Medicine and Health Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.,Laboratory of Medical Microbiology - Vaccine and Infectious Disease Institute, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
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Head LW, Coopersmith CM. Evolution of Sepsis Management: From Early Goal-Directed Therapy to Personalized Care. Adv Surg 2016; 50:221-234. [PMID: 27520874 DOI: 10.1016/j.yasu.2016.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Lyndsay W Head
- Emory University School of Medicine, 3B South, Emory University Hospital, 1364 Clifton Road, NE, Atlanta, GA 30322, USA
| | - Craig M Coopersmith
- Department of Surgery, Emory Critical Care Center, Emory University School of Medicine, 101 Woodruff Circle, Suite WMB 5105, Atlanta, GA 30322, USA.
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Lyons JD, Mittal R, Fay KT, Chen CW, Liang Z, Margoles LM, Burd EM, Farris AB, Ford ML, Coopersmith CM. Murine Lung Cancer Increases CD4+ T Cell Apoptosis and Decreases Gut Proliferative Capacity in Sepsis. PLoS One 2016; 11:e0149069. [PMID: 27018973 PMCID: PMC4809578 DOI: 10.1371/journal.pone.0149069] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 01/27/2016] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Mortality is significantly higher in septic patients with cancer than in septic patients without a history of cancer. We have previously described a model of pancreatic cancer followed by sepsis from Pseudomonas aeruginosa pneumonia in which cancer septic mice have higher mortality than previously healthy septic mice, associated with increased gut epithelial apoptosis and decreased T cell apoptosis. The purpose of this study was to determine whether this represents a common host response by creating a new model in which both the type of cancer and the model of sepsis are altered. METHODS C57Bl/6 mice received an injection of 250,000 cells of the lung cancer line LLC-1 into their right thigh and were followed three weeks for development of palpable tumors. Mice with cancer and mice without cancer were then subjected to cecal ligation and puncture and sacrificed 24 hours after the onset of sepsis or followed 7 days for survival. RESULTS Cancer septic mice had a higher mortality than previously healthy septic mice (60% vs. 18%, p = 0.003). Cancer septic mice had decreased number and frequency of splenic CD4+ lymphocytes secondary to increased apoptosis without changes in splenic CD8+ numbers. Intestinal proliferation was also decreased in cancer septic mice. Cancer septic mice had a higher bacterial burden in the peritoneal cavity, but this was not associated with alterations in local cytokine, neutrophil or dendritic cell responses. Cancer septic mice had biochemical evidence of worsened renal function, but there was no histologic evidence of renal injury. CONCLUSIONS Animals with cancer have a significantly higher mortality than previously healthy animals following sepsis. The potential mechanisms associated with this elevated mortality differ significantly based upon the model of cancer and sepsis utilized. While lymphocyte apoptosis and intestinal integrity are both altered by the combination of cancer and sepsis, the patterns of these alterations vary greatly depending on the models used.
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Affiliation(s)
- John D. Lyons
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Rohit Mittal
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Katherine T. Fay
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Ching-Wen Chen
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Zhe Liang
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Lindsay M. Margoles
- Department of Internal Medicine and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Eileen M. Burd
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Alton B. Farris
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Mandy L. Ford
- Department of Surgery and Emory Transplant Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Craig M. Coopersmith
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA, United States of America
- * E-mail:
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Hahn WO, Mikacenic C, Price BL, Harju-Baker S, Katz R, Himmelfarb J, Wurfel MM, Liles WC. Host derived biomarkers of inflammation, apoptosis, and endothelial activation are associated with clinical outcomes in patients with bacteremia and sepsis regardless of microbial etiology. Virulence 2016; 7:387-94. [PMID: 26818467 DOI: 10.1080/21505594.2016.1144003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- William O Hahn
- a Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington , Seattle , WA , USA
| | - Carmen Mikacenic
- b Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Washington , Seattle , WA , USA
| | - Brenda L Price
- c Department of Biostatistics , University of Washington , Seattle , WA , USA
| | - Susanna Harju-Baker
- b Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Washington , Seattle , WA , USA
| | - Ronit Katz
- d Kidney Research Institute, University of Washington , Seattle , WA , USA
| | | | - Mark M Wurfel
- b Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Washington , Seattle , WA , USA
| | - W Conrad Liles
- a Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington , Seattle , WA , USA
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Heat-shock response increases lung injury caused by Pseudomonas aeruginosa via an interleukin-10-dependent mechanism in mice. Anesthesiology 2014; 120:1450-62. [PMID: 24667831 DOI: 10.1097/aln.0000000000000235] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND The heat-shock response (HSR) protects from insults, such as ischemia-reperfusion injury, by inhibiting signaling pathways activated by sterile inflammation. However, the mechanisms by which the HSR activation would modulate lung damage and host response to a bacterial lung infection remain unknown. METHODS HSR was activated with whole-body hyperthermia or by intraperitoneal geldanamycin in mice that had their lungs instilled with Pseudomonas aeruginosa 24 h later (at least six mice per experimental group). Four hours after instillation, lung endothelial and epithelial permeability, bacterial counts, protein levels in bronchoalveolar lavage fluid, and lung myeloperoxidase activity were measured. Mortality rate 24 h after P. aeruginosa instillation was recorded. The HSR effect on the release of interleukin-10 and killing of P. aeruginosa bacteria by a mouse alveolar macrophage cell line and on neutrophil phagocytosis was also examined. RESULTS HSR activation worsened lung endothelial (42%) and epithelial permeability (50%) to protein, decreased lung bacterial clearance (71%), and increased mortality (50%) associated with P. aeruginosa pneumonia, an effect that was not observed in heat-shock protein-72-null mice. HSR-mediated decrease in neutrophil phagocytosis (69%) and bacterial killing (38%) by macrophages was interleukin-10 dependent, a mechanism confirmed by increased lung bacterial clearance and decreased mortality (70%) caused by P. aeruginosa pneumonia in heat-shocked interleukin-10-null mice. CONCLUSIONS Prior HSR activation worsens lung injury associated with P. aeruginosa pneumonia in mice via heat-shock protein-72- and interleukin-10-dependent mechanisms. These results provide a novel mechanism for the immunosuppression observed after severe trauma that is known to activate HSR in humans.
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Intestine-specific deletion of microsomal triglyceride transfer protein increases mortality in aged mice. PLoS One 2014; 9:e101828. [PMID: 25010671 PMCID: PMC4092051 DOI: 10.1371/journal.pone.0101828] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 06/11/2014] [Indexed: 12/16/2022] Open
Abstract
Background Mice with conditional, intestine-specific deletion of microsomal triglyceride transfer protein (Mttp-IKO) exhibit a complete block in chylomicron assembly together with lipid malabsorption. Young (8–10 week) Mttp-IKO mice have improved survival when subjected to a murine model of Pseudomonas aeruginosa-induced sepsis. However, 80% of deaths in sepsis occur in patients over age 65. The purpose of this study was to determine whether age impacts outcome in Mttp-IKO mice subjected to sepsis. Methods Aged (20–24 months) Mttp-IKO mice and WT mice underwent intratracheal injection with P. aeruginosa. Mice were either sacrificed 24 hours post-operatively for mechanistic studies or followed seven days for survival. Results In contrast to young septic Mttp-IKO mice, aged septic Mttp-IKO mice had a significantly higher mortality than aged septic WT mice (80% vs. 39%, p = 0.005). Aged septic Mttp-IKO mice exhibited increased gut epithelial apoptosis, increased jejunal Bax/Bcl-2 and Bax/Bcl-XL ratios yet simultaneously demonstrated increased crypt proliferation and villus length. Aged septic Mttp-IKO mice also manifested increased pulmonary myeloperoxidase levels, suggesting increased neutrophil infiltration, as well as decreased systemic TNFα compared to aged septic WT mice. Conclusions Blocking intestinal chylomicron secretion alters mortality following sepsis in an age-dependent manner. Increases in gut apoptosis and pulmonary neutrophil infiltration, and decreased systemic TNFα represent potential mechanisms for why intestine-specific Mttp deletion is beneficial in young septic mice but harmful in aged mice as each of these parameters are altered differently in young and aged septic WT and Mttp-IKO mice.
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L-plastin is essential for alveolar macrophage production and control of pulmonary pneumococcal infection. Infect Immun 2014; 82:1982-93. [PMID: 24595139 DOI: 10.1128/iai.01199-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report that mice deficient for the hematopoietic-specific, actin-bundling protein L-plastin (LPL) succumb rapidly to intratracheal pneumococcal infection. The increased susceptibility of LPL(-/-) mice to pulmonary pneumococcal challenge correlated with reduced numbers of alveolar macrophages, consistent with a critical role for this cell type in the immediate response to pneumococcal infection. LPL(-/-) mice demonstrated a very early clearance defect, with an almost 10-fold-higher bacterial burden in the bronchoalveolar lavage fluid 3 h following infection. Clearance of pneumococci from the alveolar space in LPL(-/-) mice was defective compared to that in Rag1(-/-) mice, which lack all B and T lymphocytes, indicating that innate immunity is defective in LPL(-/-) mice. We did not identify defects in neutrophil or monocyte recruitment or in the production of inflammatory cytokines or chemokines that would explain the early clearance defect. However, efficient alveolar macrophage regeneration following irradiation required LPL. We thus identify LPL as being key to alveolar macrophage development and essential to an effective antipneumococcal response. Further analysis of LPL(-/-) mice will illuminate critical regulators of the generation of alveolar macrophages and, thus, effective pulmonary innate immunity.
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Chen MM, Palmer JL, Plackett TP, Deburghgraeve CR, Kovacs EJ. Age-related differences in the neutrophil response to pulmonary pseudomonas infection. Exp Gerontol 2014; 54:42-6. [PMID: 24398045 DOI: 10.1016/j.exger.2013.12.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Revised: 12/18/2013] [Accepted: 12/23/2013] [Indexed: 02/06/2023]
Abstract
BACKGROUND Pseudomonas aeruginosa pneumonia is more common and more lethal in the elderly. The immunologic underpinnings of this increased incidence and mortality have not been evaluated, however are assumed to be a complication of age-associated immune dysfunction. METHODS Young (10-12week old) and aged (18-20month old) BALB/c mice were subjected to intratracheal infection of P. aeruginosa. Animals were sacrificed 24h after inoculation. The lungs were collected for analysis of lung pathology, chemokine levels, neutrophil counts, and myeloperoxidase activity. RESULTS Pulmonary levels of the neutrophil chemokine KC are significantly higher in aged mice relative to young following P. aeruginosa infection. Despite this, neutrophil counts are higher in young mice compared to aged mice after infection. Furthermore, the neutrophils are predominantly found in the air space of young infected mice. This correlated with increased myeloperoxidase activity from bronchoalveolar lavage specimens of young mice relative to aged mice after infection. CONCLUSIONS Neutrophil migration into the lungs is impaired in aged mice 24h after intratracheal infection despite elevated chemokine levels, suggesting that immunosenescence is impairing neutrophil migration.
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Affiliation(s)
- Michael M Chen
- Burn and Shock Trauma Research Institute, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Avenue, Maywood, IL 60153, USA
| | - Jessica L Palmer
- Burn and Shock Trauma Research Institute, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Avenue, Maywood, IL 60153, USA; Department of Surgery, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Avenue, Maywood, IL 60153, USA
| | - Timothy P Plackett
- Department of Surgery, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Avenue, Maywood, IL 60153, USA
| | - Cory R Deburghgraeve
- Burn and Shock Trauma Research Institute, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Avenue, Maywood, IL 60153, USA; Department of Surgery, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Avenue, Maywood, IL 60153, USA
| | - Elizabeth J Kovacs
- Burn and Shock Trauma Research Institute, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Avenue, Maywood, IL 60153, USA; Department of Surgery, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Avenue, Maywood, IL 60153, USA; Department of Microbiology and Immunology, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Avenue, Maywood, IL 60153, USA; Immunology and Aging Program, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Avenue, Maywood, IL 60153, USA.
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Inhibition of IKKβ in enterocytes exacerbates sepsis-induced intestinal injury and worsens mortality. Crit Care Med 2013; 41:e275-85. [PMID: 23939348 DOI: 10.1097/ccm.0b013e31828a44ed] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVES Nuclear factor-κB is a critical regulator of cell-survival genes and the host inflammatory response. The purpose of this study was to investigate the role of enterocyte-specific NF-kB in sepsis through selective ablation of IkB kinase. DESIGN Prospective, randomized controlled study. SETTING Animal laboratories in university medical centers. SUBJECTS AND INTERVENTIONS Mice lacking functional NF-kB in their intestinal epithelium (Vil-Cre/Ikkβ) and wild-type mice were subjected to sham laparotomy or cecal ligation and puncture. Animals were killed at 24 hours or followed 7 days for survival. MEASUREMENTS AND MAIN RESULTS Septic wild-type mice had decreased villus length compared with sham mice, whereas villus atrophy was further exacerbated in septic Vil-Cre/Ikkβ mice. Sepsis induced an increase in intestinal epithelial apoptosis compared with sham mice, which was further exacerbated in Vil-Cre/Ikkβ mice. Sepsis induced intestinal hyperpermeability in wild-type mice compared with sham mice, which was further exacerbated in septic Vil-Cre/Ikkβ mice. This was associated with increased intestinal expression of claudin-2 in septic wild-type mice, which was further increased in septic Vil-Cre/Ikkβ mice. Both, pro-inflammatory and anti-inflammatory cytokines were increased in serum following cecal ligation and puncture, and interleukin 10 and monocyte chemoattractant protein-1 levels were higher in septic Vil-Cre/Ikkβ mice than in septic wild-type mice. All septic mice were bacteremic, but no differences in bacterial load were identified between wild-type and Vil-Cre/Ikkβ mice. To determine the functional significance of these results, animals were followed for survival. Septic wild-type mice had lower mortality than septic Vil-Cre/Ikkβ mice (47% vs 80%, p<0.05). Antitumor necrosis factor administration decreased intestinal apoptosis, permeability, and mortality in wild-type septic mice, and a similar improvement in intestinal integrity and survival were seen when antitumor necrosis factor was given to Vil-Cre/Ikkβ mice. CONCLUSIONS Enterocyte-specific NF-kB has a beneficial role in sepsis by partially preventing sepsis-induced increases in apoptosis and permeability, which are associated with worsening mortality.
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Riché F, Gayat E, Collet C, Matéo J, Laisné MJ, Launay JM, Valleur P, Payen D, Cholley BP. Local and systemic innate immune response to secondary human peritonitis. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2013; 17:R201. [PMID: 24028733 PMCID: PMC4057228 DOI: 10.1186/cc12895] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 09/12/2013] [Indexed: 12/19/2022]
Abstract
Introduction Our aim was to describe inflammatory cytokines response in the peritoneum and plasma of patients with peritonitis. We also tested the hypothesis that scenarios associated with worse outcome would result in different cytokine release patterns. Therefore, we compared cytokine responses according to the occurrence of septic shock, mortality, type of peritonitis and peritoneal microbiology. Methods Peritoneal and plasma cytokines (interleukin (IL) 1, tumor necrosis factor α (TNFα), IL-6, IL-10, and interferon γ (IFNγ)) were measured in 66 patients with secondary peritonitis. Results The concentration ratio between peritoneal fluid and plasma cytokines varied from 5 (2 to 21) (IFNγ) to 1310 (145 to 3888) (IL-1). There was no correlation between plasma and peritoneal fluid concentration of any cytokine. In the plasma, TNFα, IL-6, IFNγ and IL-10 were higher in patients with shock versus no shock and in nonsurvivors versus survivors (P ≤0.03). There was no differential plasma release for any cytokine between community-acquired and postoperative peritonitis. The presence of anaerobes or Enterococcus species in peritoneal fluid was associated with higher plasma TNFα: 50 (37 to 106) versus 38 (29 to 66) and 45 (36 to 87) versus 39 (27 to 67) pg/ml, respectively (P = 0.02). In the peritoneal compartment, occurrence of shock did not result in any difference in peritoneal cytokines. Peritoneal IL-10 was higher in patients who survived (1505 (450 to 3130) versus 102 (9 to 710) pg/ml; P = 0.04). The presence of anaerobes and Enterococcus species was associated with higher peritoneal IFNγ: 2 (1 to 6) versus 10 (5 to 28) and 7 (2 to 39) versus 2 (1 to 6), P = 0.01 and 0.05, respectively). Conclusions Peritonitis triggers an acute systemic and peritoneal innate immune response with a simultaneous release of pro and anti-inflammatory cytokines. Higher levels of all cytokines were observed in the plasma of patients with the most severe conditions (shock, non-survivors), but this difference was not reflected in their peritoneal fluid. There was always a large gradient in cytokine concentration between peritoneal and plasma compartments highlighting the importance of compartmentalization of innate immune response in peritonitis.
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Hunter RA, Privett BJ, Henley WH, Breed ER, Liang Z, Mittal R, Yoseph BP, McDunn JE, Burd EM, Coopersmith CM, Ramsey JM, Schoenfisch MH. Microfluidic amperometric sensor for analysis of nitric oxide in whole blood. Anal Chem 2013; 85:6066-72. [PMID: 23692300 PMCID: PMC3712765 DOI: 10.1021/ac400932s] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Standard photolithographic techniques and a nitric oxide (NO) selective xerogel polymer were utilized to fabricate an amperometric NO microfluidic sensor with low background noise and the ability to analyze NO levels in small sample volumes (~250 μL). The sensor exhibited excellent analytical performance in phosphate buffered saline, including a NO sensitivity of 1.4 pA nM(-1), a limit of detection (LOD) of 840 pM, and selectivity over nitrite, ascorbic acid, acetaminophen, uric acid, hydrogen sulfide, ammonium, ammonia, and both protonated and deprotonated peroxynitrite (selectivity coefficients of -5.3, -4.2, -4.0, -5.0, -6.0, -5.8, -3.8, -1.5, and -4.0, respectively). To demonstrate the utility of the microfluidic NO sensor for biomedical analysis, the device was used to monitor changes in blood NO levels during the onset of sepsis in a murine pneumonia model.
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Affiliation(s)
- Rebecca A Hunter
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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The endogenous bacteria alter gut epithelial apoptosis and decrease mortality following Pseudomonas aeruginosa pneumonia. Shock 2013; 38:508-14. [PMID: 23042193 DOI: 10.1097/shk.0b013e31826e47e8] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The endogenous bacteria have been hypothesized to play a significant role in the pathophysiology of critical illness, although their role in sepsis is poorly understood. The purpose of this study was to determine how commensal bacteria alter the host response to sepsis. Conventional and germ-free (GF) C57Bl/6 mice were subjected to Pseudomonas aeruginosa pneumonia. All GF mice died within 2 days, whereas 44% of conventional mice survived for 7 days (P = 0.001). Diluting the dose of bacteria 10-fold in GF mice led to similar survival in GF and conventional mice. When animals with similar mortality were assayed for intestinal integrity, GF mice had lower levels of intestinal epithelial apoptosis but similar levels of proliferation and intestinal permeability. Germ-free mice had significantly lower levels of tumor necrosis factor and interleukin 1β in bronchoalveolar lavage fluid compared with conventional mice without changes in systemic cytokine production. Under conventional conditions, sepsis unmasks lymphocyte control of intestinal epithelial apoptosis, because sepsis induces a greater increase in gut apoptosis in Rag-1 mice than in wild-type mice. However, in a separate set of experiments, gut apoptosis was similar between septic GF Rag-1 mice and septic GF wild-type mice. These data demonstrate that the endogenous bacteria play a protective role in mediating mortality from pneumonia-induced sepsis, potentially mediated through altered intestinal apoptosis and the local proinflammatory response. In addition, sepsis-induced lymphocyte-dependent increases in gut epithelial apoptosis appear to be mediated by the endogenous bacteria.
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Bordon J, Aliberti S, Fernandez-Botran R, Uriarte SM, Rane MJ, Duvvuri P, Peyrani P, Morlacchi LC, Blasi F, Ramirez JA. Understanding the roles of cytokines and neutrophil activity and neutrophil apoptosis in the protective versus deleterious inflammatory response in pneumonia. Int J Infect Dis 2013; 17:e76-83. [DOI: 10.1016/j.ijid.2012.06.006] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 06/22/2012] [Accepted: 06/22/2012] [Indexed: 02/03/2023] Open
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Dominguez JA, Xie Y, Dunne WM, Yoseph BP, Burd EM, Coopersmith CM, Davidson NO. Intestine-specific Mttp deletion decreases mortality and prevents sepsis-induced intestinal injury in a murine model of Pseudomonas aeruginosa pneumonia. PLoS One 2012; 7:e49159. [PMID: 23145105 PMCID: PMC3493497 DOI: 10.1371/journal.pone.0049159] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 10/04/2012] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The small intestine plays a crucial role in the pathophysiology of sepsis and has been referred to as the "motor" of the systemic inflammatory response. One proposed mechanism is that toxic gut-derived lipid factors, transported in mesenteric lymph, induce systemic injury and distant organ failure. However, the pathways involved are yet to be defined and the role of intestinal chylomicron assembly and secretion in transporting these lipid factors is unknown. Here we studied the outcome of sepsis in mice with conditional, intestine-specific deletion of microsomal triglyceride transfer protein (Mttp-IKO), which exhibit a block in chylomicron assembly together with lipid malabsorption. METHODOLOGY/PRINCIPAL FINDINGS Mttp-IKO mice and controls underwent intratracheal injection with either Pseudomonas aeruginosa or sterile saline. Mttp-IKO mice exhibited decreased seven-day mortality, with 0/20 (0%) dying compared to 5/17 (29%) control mice (p<0.05). This survival advantage in Mttp-IKO mice, however, was not associated with improvements in pulmonary bacterial clearance or neutrophil infiltration. Rather, Mttp-IKO mice exhibited protection against sepsis-associated decreases in villus length and intestinal proliferation and were also protected against increased intestinal apoptosis, both central features in control septic mice. Serum IL-6 levels, a major predictor of mortality in human and mouse models of sepsis, were elevated 8-fold in septic control mice but remained unaltered in septic Mttp-IKO mice. Serum high density lipoprotein (HDL) levels were reduced in septic control mice but were increased in septic Mttp-IKO mice. The decreased levels of HDL were associated with decreased hepatic expression of apolipoprotein A1 in septic control mice. CONCLUSIONS/SIGNIFICANCE These studies suggest that strategies directed at blocking intestinal chylomicron secretion may attenuate the progression and improve the outcome of sepsis through effects mediated by metabolic and physiological adaptations in both intestinal and hepatic lipid flux.
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Affiliation(s)
- Jessica A. Dominguez
- Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Yan Xie
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - W. Michael Dunne
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Benyam P. Yoseph
- Emory Center for Critical Care and Department of Surgery, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Eileen M. Burd
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Craig M. Coopersmith
- Emory Center for Critical Care and Department of Surgery, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Nicholas O. Davidson
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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Mechanisms of methicillin-resistant Staphylococcus aureus pneumonia-induced intestinal epithelial apoptosis. Shock 2012; 38:68-75. [PMID: 22592747 DOI: 10.1097/shk.0b013e318259abdb] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia-induced sepsis is a common cause of morbidity in the intensive care unit. Although pneumonia is initiated in the lungs, extrapulmonary manifestations occur commonly. In light of the key role the intestine plays in the pathophysiology of sepsis, we sought to determine whether MRSA pneumonia induces intestinal injury. FVB/N mice were subjected to MRSA or sham pneumonia and killed 24 h later. Septic animals had a marked increase in intestinal epithelial apoptosis by both hematoxylin-eosin and active caspase 3 staining. Methicillin-resistant S. aureus-induced intestinal apoptosis was associated with an increase in the expression of the proapoptotic proteins Bid and Bax and the antiapoptotic protein Bcl-xL in the mitochondrial pathway. In the receptor-mediated pathway, MRSA pneumonia induced an increase in Fas ligand but decreased protein levels of Fas, FADD, pFADD, TNF-R1, and TRADD. To assess the functional significance of these changes, MRSA pneumonia was induced in mice with genetic manipulations in proteins in either the mitochondrial or receptor-mediated pathways. Both Bid-/- mice and animals with intestine-specific overexpression of Bcl-2 had decreased intestinal apoptosis compared with wild-type animals. In contrast, Fas ligand-/- mice had no alterations in apoptosis. To determine if these findings were organism-specific, similar experiments were performed in mice subjected to Pseudomonas aeruginosa pneumonia. Pseudomonas aeruginosa induced gut apoptosis, but unlike MRSA, this was associated with increased Bcl-2 and TNF-R1 and decreased Fas. Methicillin-resistant S. aureus pneumonia thus induces organism-specific changes in intestinal apoptosis via changes in both the mitochondrial and receptor-mediated pathways, although the former may be more functionally significant.
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Epidermal growth factor improves survival and prevents intestinal injury in a murine model of pseudomonas aeruginosa pneumonia. Shock 2012; 36:381-9. [PMID: 21701422 DOI: 10.1097/shk.0b013e31822793c4] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mortality from pneumonia is mediated, in part, through extrapulmonary causes. Epidermal growth factor (EGF) has broad cytoprotective effects, including potent restorative properties in the injured intestine. The purpose of this study was to determine the efficacy of EGF treatment following Pseudomonas aeruginosa pneumonia. FVB/N mice underwent intratracheal injection of either P. aeruginosa or saline and were then randomized to receive either systemic EGF or vehicle beginning immediately or 24 h after the onset of pneumonia. Systemic EGF decreased 7-day mortality from 65% to 10% when initiated immediately after the onset of pneumonia and to 27% when initiated 24 h after the onset of pneumonia. Even though injury in pneumonia is initiated in the lungs, the survival advantage conferred by EGF was not associated with improvements in pulmonary pathology. In contrast, EGF prevented intestinal injury by reversing pneumonia-induced increases in intestinal epithelial apoptosis and decreases in intestinal proliferation and villus length. Systemic cytokines and kidney and liver function were unaffected by EGF therapy, although EGF decreased pneumonia-induced splenocyte apoptosis. To determine whether the intestine was sufficient to account for extrapulmonary effects induced by EGF, a separate set of experiments was done using transgenic mice with enterocyte-specific overexpression of EGF (IFABP-EGF [intestinal fatty acid-binding protein linked to mouse EGF] mice), which were compared with wild-type mice subjected to pneumonia. IFABP-EGF mice had improved survival compared with wild-type mice following pneumonia (50% vs. 28%, respectively, P < 0.05) and were protected from pneumonia-induced intestinal injury. Thus, EGF may be a potential adjunctive therapy for pneumonia, mediated in part by its effects on the intestine.
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Age-related defects in TLR2 signaling diminish the cytokine response by alveolar macrophages during murine pneumococcal pneumonia. Exp Gerontol 2012; 47:507-18. [PMID: 22548913 DOI: 10.1016/j.exger.2012.04.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 04/12/2012] [Accepted: 04/16/2012] [Indexed: 01/09/2023]
Abstract
Alveolar macrophages (AMs) are the first immune cells to respond to an invading pathogen and coordinate the inflammatory response within the lungs. Studies suggest that macrophages exhibit age-related deficiencies in Toll-like receptor (TLR) function; however, the impact of this dysfunction during pneumonia, the leading cause of infectious death in the elderly, and the underlying mechanisms responsible remain unclear. We examined disease severity in young, mature, and aged BALB/cBy mice following intratracheal infection with the Gram-positive bacteria Streptococcus pneumoniae (Spn). Both mature and aged mice failed to clear bacteria and as a result had increased mortality, tissue damage and vascular leakage. Early production of TNFα, IL-1β, and IL-6 during pneumonia declined with age and was associated with an inability of isolated AMs to respond to pneumococcal cell wall (CW) and ethanol-killed Spn ex vivo. Total levels of TLR1 were unaffected by age and TLR2 surface expression was slightly yet significantly increased on aged AMs suggesting that intracellular TLR signaling defects were responsible for the age-related decline in cytokine responsiveness. Following infection of isolated AMs with live Spn, a significant age-related decline in TLR2-induced phosphorylation of p65 NFκB, JNK and p38 MAPK, and an increase in ERK phosphorylation was observed by immunoblotting. These data are the first to demonstrate that TLR2-dependent recognition of Spn by aged AMs is impaired and is associated with a delayed pro-inflammatory cytokine response in vivo along with enhanced susceptibility to pneumococcal pneumonia.
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Cecal ligation and puncture followed by methicillin-resistant Staphylococcus aureus pneumonia increases mortality in mice and blunts production of local and systemic cytokines. Shock 2012; 37:85-94. [PMID: 21937950 DOI: 10.1097/shk.0b013e3182360faf] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Mortality in the intensive care unit frequently results from the synergistic effect of two temporally distinct infections. This study examined the pathophysiology of a new model of intra-abdominal sepsis followed by methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. Mice underwent cecal ligation and puncture (CLP) or sham laparotomy followed 3 days later by an intratracheal injection of MRSA or saline. Both CLP/saline and sham/MRSA mice had 100% survival, whereas animals with CLP followed by MRSA pneumonia had 67% 7-day survival. Animals subjected to CLP/MRSA had increased bronchoalveolar lavage concentrations of MRSA compared with sham/MRSA animals. Animals subjected to sham/MRSA pneumonia had increased bronchoalveolar lavage levels of interleukin 6 (IL-6), tumor necrosis factor α, and granulocyte colony-stimulating factor compared with those given intratracheal saline, whereas CLP/MRSA mice had a blunted local inflammatory response with markedly decreased cytokine levels. Similarly, animals subjected to CLP/saline had increased peritoneal lavage levels of IL-6 and IL-1β compared with those subjected to sham laparotomy, whereas this response was blunted in CLP/MRSA mice. Systemic cytokines were upregulated in both CLP/saline and sham/MRSA mice, and this was blunted by the combination of CLP/MRSA. In contrast, no synergistic effect on pneumonia severity, white blood cell count, or lymphocyte apoptosis was identified in CLP/MRSA mice compared with animals with either insult in isolation. These results indicate that a clinically relevant model of CLP followed by MRSA pneumonia causes higher mortality than could have been predicted from studying either infection in isolation, and this was associated with a blunted local (pulmonary and peritoneal) and systemic inflammatory response and decreased ability to clear infection.
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The innate immune response to Streptococcus pneumoniae in the lung depends on serotype and host response. Vaccine 2011; 29:8002-11. [PMID: 21864623 DOI: 10.1016/j.vaccine.2011.08.064] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 07/22/2011] [Accepted: 08/12/2011] [Indexed: 11/24/2022]
Abstract
Bacteremic pneumonia with some pneumococcal capsular serotypes, including serotype 3 (ST3), has been associated with a higher risk of death, whereas others, such as ST8, are associated with a lower risk. To provide a molecular basis for understanding such differences, we used oligo cDNA microarrays to analyze and compare the gene expression profiles of the lungs of Balb/c mice infected intranasally with either ST3, strain A66.1, or ST8, strain ATCC 6308 (6308). Compared to uninfected controls, infection with either A66.1 or 6308 led to inoculum-dependent expression of IFN-γ inducible CXC chemokines among other pro-inflammatory genes. To investigate the role that IFN-γ inducible chemokines CXCL9, CXCL10 and CXCL11 play in A66.1- and 6308-induced pneumonia, we examined the effect of the absence of their common receptor, CXCR3, on intranasal infection in CXCR3(-/-) (Balb/c) mice. Compared to wild type (WT) mice, virulence of A66.1 but not 6308 was attenuated in CXCR3(-/-) mice. A66.1-infected CXCR3(-/-) mice had fewer lung neutrophils and more alveolar macrophages 48 h after infection and fewer blood CFU 72 h after infection. Histopathological examination of lung sections revealed less inflammation among A66.1-infected CXCR3(-/-) than WT mice. The reduced virulence of A66.1 in CXCR3(-/-) mice suggests that inhibition of the functional activity of IFN-γ inducible chemokines modulates the host response to A66.1, in turn suggesting a novel approach to improve vaccine-mediated protection against ST3 pneumonia.
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The β-human chorionic gonadotropin-related peptide LQGV reduces mortality and inflammation in a murine polymicrobial sepsis model. Crit Care Med 2011; 39:126-34. [PMID: 20890188 DOI: 10.1097/ccm.0b013e3181fa3a93] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Mortality in sepsis remains high and efforts to modulate the inflammatory response so far mostly failed to improve survival. The human chorionic gonadotropin-related tetrapeptide LQGV was recently shown to exert anti-inflammatory activity. The aim of this study was to assess the effect of LQGV on cecal ligation and puncture-induced mortality and inflammation. DESIGN Animal study. SETTING University research laboratory. SUBJECTS Male C57BL/6 mice. INTERVENTIONS To examine the effect of LQGV by itself on cecal ligation and puncture-induced mortality and inflammation, C57BL/6 mice were exposed to a moderate cecal ligation and puncture procedure (40% ligation and double puncture) with a mortality rate of approximately 80% within 5 days in control mice. In addition, to examine whether LQGV was of additive value to standard sepsis care (antibiotics and fluid resuscitation), a more severe cecal ligation and puncture procedure was used (80% ligation and double puncture), yielding approximately 100% mortality within 12 days in control mice. LQGV (5 mg/kg body weight), phosphate-buffered saline (as control), or dexamethasone (2.5 mg/kg body weight) was administered perioperatively. Survival was monitored for 21 days and inflammatory markers were determined in plasma, peritoneal cavity, and lungs. MEASUREMENTS AND MAIN RESULTS LQGV significantly improved survival from 20% to 50% during the first 5 days after moderate cecal ligation and puncture. This was associated with reduced cytokine and E-selectin levels in peritoneal lavage fluid, lungs, and, to a lesser extent, in plasma. LQGV treatment also reduced pulmonary nuclear factor-κB activation and pulmonary damage. In the severe cecal ligation and puncture model, LQGV combined with fluid resuscitation and antibiotics resulted in significantly better survival (70%) than that observed with fluid resuscitation and antibiotics alone (30%). CONCLUSIONS LQGV improves survival after cecal ligation and puncture. This is likely established by a modest reduction of the acute inflammatory response through a nuclear factor-κB-dependent mechanism. Furthermore, LQGV may be a valuable additive next to the standard care in polymicrobial sepsis.
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McConnell KW, Fox AC, Clark AT, Chang NYN, Dominguez JA, Farris AB, Buchman TG, Hunt CR, Coopersmith CM. The role of heat shock protein 70 in mediating age-dependent mortality in sepsis. THE JOURNAL OF IMMUNOLOGY 2011; 186:3718-25. [PMID: 21296977 DOI: 10.4049/jimmunol.1003652] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Sepsis is primarily a disease of the aged, with increased incidence and mortality occurring in aged hosts. Heat shock protein (HSP) 70 plays an important role in both healthy aging and the stress response to injury. The purpose of this study was to determine the role of HSP70 in mediating mortality and the host inflammatory response in aged septic hosts. Sepsis was induced in both young (6- to 12-wk-old) and aged (16- to 17-mo-old) HSP70(-/-) and wild-type (WT) mice to determine whether HSP70 modulated outcome in an age-dependent fashion. Young HSP70(-/-) and WT mice subjected to cecal ligation and puncture, Pseudomonas aeruginosa pneumonia, or Streptococcus pneumoniae pneumonia had no differences in mortality, suggesting HSP70 does not mediate survival in young septic hosts. In contrast, mortality was higher in aged HSP70(-/-) mice than aged WT mice subjected to cecal ligation and puncture (p = 0.01), suggesting HSP70 mediates mortality in sepsis in an age-dependent fashion. Compared with WT mice, aged septic HSP70(-/-) mice had increased gut epithelial apoptosis and pulmonary inflammation. In addition, HSP70(-/-) mice had increased systemic levels of TNF-α, IL-6, IL-10, and IL-1β compared with WT mice. These data demonstrate that HSP70 is a key determinant of mortality in aged, but not young hosts in sepsis. HSP70 may play a protective role in an age-dependent response to sepsis by preventing excessive gut apoptosis and both pulmonary and systemic inflammation.
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Affiliation(s)
- Kevin W McConnell
- Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
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Bakthavatchalu V, Meka A, Sathishkumar S, Lopez MC, Verma RK, Wallet SM, Bhattacharyya I, Boyce BF, Mans JJ, Lamont RJ, Baker HV, Ebersole JL, Kesavalu L. Molecular characterization of Treponema denticola infection-induced bone and soft tissue transcriptional profiles. Mol Oral Microbiol 2010; 25:260-74. [PMID: 20618700 DOI: 10.1111/j.2041-1014.2010.00575.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Treponema denticola is associated with subgingival biofilms in adult periodontitis and with acute necrotizing ulcerative gingivitis. However, the molecular mechanisms by which T. denticola impacts periodontal inflammation and alveolar bone resorption remain unclear. Here, we examined changes in the host transcriptional profiles during a T. denticola infection using a murine calvarial model of inflammation and bone resorption. T. denticola was injected into the subcutaneous soft tissue over the calvaria of BALB/c mice for 3 days, after which the soft tissues and the calvarial bones were excised. RNA was isolated and analysed for transcript profiling using Murine GeneChip arrays. Following T. denticola infection, 2905 and 1234 genes in the infected calvarial bones and soft tissues, respectively, were differentially expressed (P <or= 0.05). Biological pathways significantly impacted by T. denticola infection in calvarial bone and calvarial tissue included leukocyte transendothelial migration, cell adhesion (immune system) molecules, cell cycle, extracellular matrix-receptor interaction, focal adhesion, B-cell receptor signaling and transforming growth factor-beta signaling pathways resulting in proinflammatory, chemotactic effects, and T-cell stimulation. In conclusion, localized T. denticola infection differentially induces transcription of a broad array of host genes, the profiles of which differed between inflamed calvarial bone and soft tissues.
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Affiliation(s)
- V Bakthavatchalu
- Center for Oral Health Research, College of Dentistry, University of Kentucky, Lexington, KY, USA
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Evans SE, Tuvim MJ, Zhang J, Larson DT, García CD, Martinez-Pro S, Coombes KR, Dickey BF. Host lung gene expression patterns predict infectious etiology in a mouse model of pneumonia. Respir Res 2010; 11:101. [PMID: 20653947 PMCID: PMC2914038 DOI: 10.1186/1465-9921-11-101] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Accepted: 07/23/2010] [Indexed: 11/28/2022] Open
Abstract
Background Lower respiratory tract infections continue to exact unacceptable worldwide mortality, often because the infecting pathogen cannot be identified. The respiratory epithelia provide protection from pneumonias through organism-specific generation of antimicrobial products, offering potential insight into the identity of infecting pathogens. This study assesses the capacity of the host gene expression response to infection to predict the presence and identity of lower respiratory pathogens without reliance on culture data. Methods Mice were inhalationally challenged with S. pneumoniae, P. aeruginosa, A. fumigatus or saline prior to whole genome gene expression microarray analysis of their pulmonary parenchyma. Characteristic gene expression patterns for each condition were identified, allowing the derivation of prediction rules for each pathogen. After confirming the predictive capacity of gene expression data in blinded challenges, a computerized algorithm was devised to predict the infectious conditions of subsequent subjects. Results We observed robust, pathogen-specific gene expression patterns as early as 2 h after infection. Use of an algorithmic decision tree revealed 94.4% diagnostic accuracy when discerning the presence of bacterial infection. The model subsequently differentiated between bacterial pathogens with 71.4% accuracy and between non-bacterial conditions with 70.0% accuracy, both far exceeding the expected diagnostic yield of standard culture-based bronchoscopy with bronchoalveolar lavage. Conclusions These data substantiate the specificity of the pulmonary innate immune response and support the feasibility of a gene expression-based clinical tool for pneumonia diagnosis.
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Affiliation(s)
- Scott E Evans
- Department of Pulmonary Medicine, University of Texas-M D, Anderson Cancer Center, Houston, Texas, USA.
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Abstract
Despite the expression of a myriad of virulence factors, healthy individuals are generally able to resist infections with Pseudomonas aeruginosa. Polymorphonuclear leukocyte-dependent killing is the major mechanism responsible for resistance; dysregulation of host defense mechanisms in addition to expression of specific bacterial factors can result in life-threatening infections with this bacterium.
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Affiliation(s)
- Joanna B Goldberg
- Department of Microbiology, University of Virginia Health System Box 800734, Charlottesville, VA 22908-0734 USA
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