Effects of Antibiotic Therapy on Pseudomonas aeruginosa-Induced Lung Injury in a Rat Model

ABSTRACT The effect of antibiotics on the acute lung injury induced by virulent Pseudomonas aeruginosa PA103 was quantitatively analyzed in a rat model. Lung injury was induced by the instillation of PA103 directly into the right lower lobes of the lungs of anesthetized rats. The alveolar epithelial injury, extravascular lung water, and total plasma equivalents were measured as separate, independent parameters of acute lung injury. Four hours after the instillation of PA103, all the parameters were increased linearly depending on the dose of P. aeruginosa. Next, we examined the effects of intravenously administered antibiotics on the parameters of acute lung injury in d-galactosamine-sensitized rats. One hour after the rats received 107 CFU of PA103, an intravenous bolus injection of aztreonam (60 mg/kg) or imipenem-cilastatin (30 mg/kg) was administered. Despite an MIC indicating resistance, imipenem-cilastatin improved all the measurements of lung injury; in contrast, aztreonam, which had an MIC indicating sensitivity, did not improve any of the lung injury parameters. The antibiotics did not generate different quantities of plasma endotoxin; therefore, endotoxin did not appear to explain the differences in lung injury. This in vivo model is useful to quantitatively compare the efficacies of parenteral antibiotic administration on Pseudomonas airspace infections.

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Dexmedetomidine alleviates pulmonary edema through the epithelial sodium channel (ENaC) via the PI3K/Akt/Nedd4-2 pathway in LPS-induced acute lung injury

Immunologic Research ◽

10.1007/s12026-021-09176-6 ◽

2021 ◽

Author(s):

Yuanxu Jiang ◽

Mingzhu Xia ◽

Jing Xu ◽

Qiang Huang ◽

Zhongliang Dai ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Sodium Channel ◽

Pulmonary Edema ◽

Cell Injury ◽

A549 Cells ◽

Alveolar Epithelial ◽

Phosphorylated Akt ◽

Epithelial Sodium Channel Enac

AbstractDexmedetomidine (Dex), a highly selective α2-adrenergic receptor (α2AR) agonist, has an anti-inflammatory property and can alleviate pulmonary edema in lipopolysaccharide (LPS)-induced acute lung injury (ALI), but the mechanism is still unclear. In this study, we attempted to investigate the effect of Dex on alveolar epithelial sodium channel (ENaC) in the modulation of alveolar fluid clearance (AFC) and the underlying mechanism. Lipopolysaccharide (LPS) was used to induce acute lung injury (ALI) in rats and alveolar epithelial cell injury in A549 cells. In vivo, Dex markedly reduced pulmonary edema induced by LPS through promoting AFC, prevented LPS-induced downregulation of α-, β-, and γ-ENaC expression, attenuated inflammatory cell infiltration in lung tissue, reduced the concentrations of TNF-α, IL-1β, and IL-6, and increased concentrations of IL-10 in bronchoalveolar lavage fluid (BALF). In A549 cells stimulated with LPS, Dex attenuated LPS-mediated cell injury and the downregulation of α-, β-, and γ-ENaC expression. However, all of these effects were blocked by the PI3K inhibitor LY294002, suggesting that the protective role of Dex is PI3K-dependent. Additionally, Dex increased the expression of phosphorylated Akt and reduced the expression of Nedd4-2, while LY294002 reversed the effect of Dex in vivo and in vitro. Furthermore, insulin-like growth factor (IGF)-1, a PI3K agonists, promoted the expression of phosphorylated Akt and reduced the expression of Nedd4-2 in LPS-stimulated A549 cells, indicating that Dex worked through PI3K, and Akt and Nedd4-2 are downstream of PI3K. In conclusion, Dex alleviates pulmonary edema by suppressing inflammatory response in LPS-induced ALI, and the mechanism is partly related to the upregulation of ENaC expression via the PI3K/Akt/Nedd4-2 signaling pathway.

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Adrenomedullin expression in a rat model of acute lung injury induced by hypoxia and LPS

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00314.2004 ◽

2005 ◽

Vol 288 (3) ◽

pp. L536-L545 ◽

Cited By ~ 19

Author(s):

Jackeline Agorreta ◽

Javier J. Zulueta ◽

Luis M. Montuenga ◽

Mercedes Garayoa

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Cell Lines ◽

Rat Model ◽

In Vitro Model ◽

Rat Lung ◽

Vitro Model

Adrenomedullin (ADM) is upregulated independently by hypoxia and LPS, two key factors in the pathogenesis of acute lung injury (ALI). This study evaluates the expression of ADM in ALI using experimental models combining both stimuli: an in vivo model of rats treated with LPS and acute normobaric hypoxia (9% O2) and an in vitro model of rat lung cell lines cultured with LPS and exposed to hypoxia (1% O2). ADM expression was analyzed by in situ hybridization, Northern blot, Western blot, and RIA analyses. In the rat lung, combination of hypoxia and LPS treatments overcomes ADM induction occurring after each treatment alone. With in situ techniques, the synergistic effect of both stimuli mainly correlates with ADM expression in inflammatory cells within blood vessels and, to a lesser extent, to cells in the lung parenchyma and bronchiolar epithelial cells. In the in vitro model, hypoxia and hypoxia + LPS treatments caused a similar strong induction of ADM expression and secretion in epithelial and endothelial cell lines. In alveolar macrophages, however, LPS-induced ADM expression and secretion were further increased by the concomitant exposure to hypoxia, thus paralleling the in vivo response. In conclusion, ADM expression is highly induced in a variety of key lung cell types in this rat model of ALI by combination of hypoxia and LPS, suggesting an essential role for this mediator in this syndrome.

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Effect of cyclooxygenase inhibition on ethchlorvynol-induced acute lung injury in dogs

Journal of Applied Physiology ◽

10.1152/jappl.1986.61.3.1058 ◽

1986 ◽

Vol 61 (3) ◽

pp. 1058-1064 ◽

Cited By ~ 10

Author(s):

R. S. Sprague ◽

A. H. Stephenson ◽

T. E. Dahms ◽

A. J. Lonigro

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Vascular Reactivity ◽

Arachidonic Acid Metabolism ◽

Cyclooxygenase Inhibitors ◽

Lung Water ◽

Edema Formation ◽

Cyclooxygenase Inhibition ◽

Cyclooxygenase Activity ◽

The Right

In anesthetized dogs ethchlorvynol (ECV, 9 mg/kg) was selectively administered into the right pulmonary circulation to produce unilateral acute lung injury (ALI) characterized by nonhydrostatic pulmonary edema and systemic hypoxemia. To investigate the hypothesis that products of cyclooxygenase activity are mediators of the arterial hypoxemia, but not the edema formation in this injury, animals were pretreated with one of two chemically dissimilar cyclooxygenase inhibitors, indomethacin (5 mg/kg), or ibuprofen (12.5 mg/kg), or vehicle (0.1 M sodium carbonate) prior to the administration of ECV. Pretreatment with either inhibitor prevented the ECV-induced systemic hypoxemia observed in animals pretreated with vehicle (P less than 0.01). Despite this protection of systemic oxygenation, there was no redistribution of blood flow to the uninjured lung following unilateral ECV administration. Cyclooxygenase inhibition prior to ALI did not attenuate the accumulation of lung water. In the ibuprofen group, left atrial pressure increased significantly following ECV administration. We conclude that a product(s) of cyclooxygenase-mediated arachidonic acid metabolism is responsible for the altered vascular reactivity and consequent systemic hypoxemia in this model, but that the edema formation following ECV is not related to cyclooxygenase activity. In addition, ibuprofen, administered prior to the induction of ALI, exhibits properties not shared by indomethacin but is not different in its capacity to attenuate hypoxemia or in its failure to limit edema formation.

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Role of LecA and LecB Lectins in Pseudomonas aeruginosa-Induced Lung Injury and Effect of Carbohydrate Ligands

Infection and Immunity ◽

10.1128/iai.01204-08 ◽

2009 ◽

Vol 77 (5) ◽

pp. 2065-2075 ◽

Cited By ~ 172

Author(s):

Chanez Chemani ◽

Anne Imberty ◽

Sophie de Bentzmann ◽

Maud Pierre ◽

Michaela Wimmerová ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Acute Lung Injury ◽

Lung Injury ◽

Parental Strain ◽

A549 Cells ◽

Carbohydrate Ligands ◽

Vitro Model

ABSTRACT Pseudomonas aeruginosa is a frequently encountered pathogen that is involved in acute and chronic lung infections. Lectin-mediated bacterium-cell recognition and adhesion are critical steps in initiating P. aeruginosa pathogenesis. This study was designed to evaluate the contributions of LecA and LecB to the pathogenesis of P. aeruginosa-mediated acute lung injury. Using an in vitro model with A549 cells and an experimental in vivo murine model of acute lung injury, we compared the parental strain to lecA and lecB mutants. The effects of both LecA- and Lec B-specific lectin-inhibiting carbohydrates (α-methyl-galactoside and α-methyl-fucoside, respectively) were evaluated. In vitro, the parental strain was associated with increased cytotoxicity and adhesion on A549 cells compared to the lecA and lecB mutants. In vivo, the P. aeruginosa-induced increase in alveolar barrier permeability was reduced with both mutants. The bacterial burden and dissemination were decreased for both mutants compared with the parental strain. Coadministration of specific lectin inhibitors markedly reduced lung injury and mortality. Our results demonstrate that there is a relationship between lectins and the pathogenicity of P. aeruginosa. Inhibition of the lectins by specific carbohydrates may provide new therapeutic perspectives.

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Nasal potential difference to detect Na+channel dysfunction in acute lung injury

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00223.2010 ◽

2011 ◽

Vol 300 (3) ◽

pp. L305-L318 ◽

Cited By ~ 9

Author(s):

R. Mac Sweeney ◽

H. Fischer ◽

D. F. McAuley

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Ion Channel ◽

Pulmonary Edema ◽

Potential Difference ◽

Na Channel ◽

Alveolar Epithelial ◽

Nasal Potential Difference ◽

Respiratory Epithelial

Pulmonary fluid clearance is regulated by the active transport of Na+and Cl−through respiratory epithelial ion channels. Ion channel dysfunction contributes to the pathogenesis of various pulmonary fluid disorders including high-altitude pulmonary edema (HAPE) and neonatal respiratory distress syndrome (RDS). Nasal potential difference (NPD) measurement allows an in vivo investigation of the functionality of these channels. This technique has been used for the diagnosis of cystic fibrosis, the archetypal respiratory ion channel disorder, for over a quarter of a century. NPD measurements in HAPE and RDS suggest constitutive and acquired dysfunction of respiratory epithelial Na+channels. Acute lung injury (ALI) is characterized by pulmonary edema due to alveolar epithelial-interstitial-endothelial injury. NPD measurement may enable identification of critically ill ALI patients with a susceptible phenotype of dysfunctional respiratory Na+channels and allow targeted therapy toward Na+channel function.

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A Two-Event In Vivo Model of Transfusion-Related Acute Lung Injury.

Blood ◽

10.1182/blood.v108.11.19.19 ◽

2006 ◽

Vol 108 (11) ◽

pp. 19-19 ◽

Cited By ~ 1

Author(s):

Christopher C. Silliman ◽

Marguerite Kelher ◽

Tomohiko Masuno ◽

Ernest E. Moore ◽

Sagar Damle ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Mhc Class I ◽

Mhc Class Ii ◽

Normal Saline ◽

Class Ii ◽

Class I ◽

In Vivo Model ◽

Blue Dye

Abstract TRALI is the most common cause of transfusion-related death in the US, and the pathogenesis is related to the infusion of donor anti-leukocyte antibodies or biologic response modifiers (BRMs) including lipids that accumulate during storage of cellular components. We hypothesize that TRALI is the result of two distinct events: the first related to the clinical condition of the patient resulting in pulmonary endothelial activation and sequestration of PMNs and the second is the infusion of antibodies or BRMs along with the transfused product. Methods: PRBCs were obtained from 5 donors and 50% were pre-storage leukoreduced by filtration and the other 50% left as a control, and both stored per AABB criteria. Plasma samples were obtained serially from these units and was heat-treated (56°C for 30 min) to destroy fibrinogen and complement prior to administration. Antibodies to antigens present on leukocytes from Sprague Dawley rats including MHC class I: OX18 & OX27, MHC class II: OX3 & OX6 and anti-granulocyte (PMN) antibodies were obtained commercially. Male rats were given saline (NS) or 2 mg/kg IP of endotoxin (LPS S.enteritidies, non-lethal), incubated for 2 hrs, anesthetized with pentobarbital, the femoral vessels were cannulated, and 10% of the blood volume was withdrawn over 15 min. Plasma from day 1 (10% final) and day 42 (5–10%) PRBCs and 10% LR-PRBCs, and 50 or 100 μg of antibodies (500μl of sera, anti-PMN) were infused over 30 min, followed by IV Evan’s Blue dye (30 mg/kg; 1ml) that binds to albumin. At 6 hours, plasma and bronchoalveolar lavage (BAL) fluid were obtained to determine the % of Evan’s Blue leak into the BAL at 620 nm. Mortality was < 5%. Acute lung injury (ALI) was precipitated in LPS-treated animals by day 42 PRBC plasma (5% & 10%), 10% day 42 LR-PRBC plasma and antibodies to MHC class I antigens (Table). With NS as the first event, rats did not evidence ALI for all groups, including MHC class I antibodies. Moreover, in LPS pre-treated rats, second events consisting of NS, day 0 PRBC, day 0 LR-PRBC plasma, antibodies to MHC class II antigens (OX3 & OX6) and anti-PMN antibodies did not elicit ALI (Table). We conclude that 1) this in vivo model approximates the mortality of the clinical condition, 2) it demonstrates that the pathogenesis requires two events to elicit antibody-induced or BRM-mediated TRALI, and 3) ALI as the result of LPS/MHC class I antibodies evidences a dose-response. ALI as a a Function of Evans Blue Dye Leak 1st Event ⇒ Normal Saline NS LPS 2nd Event ⇓ †=p<.05 vs. 1st event or 2nd event Normal Saline 0.08±0.03 0.24±0.11 MHC Class I OX18 50μg 0.06±0.06 0.18±0.03 MHC Class I OX18 100μg 0.17 1.91±0.7] MHC Class I OX27 50μg 0.19±0.04 1.26±0.1† MHC Class II OX3 50μg 0.07 0.4 MHC Class II OX6 50μg 0.07±0.07 0.2±0.07 Anti-Granulocyte serum 500μl 0.25±0.14 0.22±0.17 Anti-Granulocyte 100μg 0.174 0.09±.02 PRBCs day 1 [10%] 0.10±0.08 0.25±0.09 PRBCs day 42 [5%] 0.13±0.07 2.48±0.46† PRBCs day 42 [10%] 0.16±0.10 1.16±0.34† LR-PRBCs day 1 [10%] 0.16±0.09 0.19±0.05 LR-PRBCs day 42 [10%] 0.20±0.12 2.69±0.58†

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Acute Systemic Reaction and Lung Alterations Induced by an Antiplatelet Integrin gpIIb/IIIa Antibody in Mice

Blood ◽

10.1182/blood.v94.2.684.414k36_684_693 ◽

1999 ◽

Vol 94 (2) ◽

pp. 684-693 ◽

Cited By ~ 3

Author(s):

Bernhard Nieswandt ◽

Bernd Echtenacher ◽

Frank-Peter Wachs ◽

Josef Schröder ◽

J. Engelbert Gessner ◽

...

Keyword(s):

Acute Lung Injury ◽

Tumor Necrosis Factor ◽

Lung Injury ◽

Tumor Necrosis ◽

Systemic Reaction ◽

In Vivo Model ◽

Platelet Surface ◽

Necrosis Factor

Shock is frequently accompanied by thrombocytopenia. To investigate the pathogenic role of platelets in shock, we examined the in vivo effects of monoclonal antibodies (MoAbs) against mouse platelet membrane proteins. Injection of the platelet-specific MoAb MWReg30 to the fibrinogen receptor (gpIIb/IIIa) rendered mice severely hypothermic within minutes. Isotype-matched control antibodies, even if they also recognized platelet surface antigens, did not induce comparable signs. MWReg30 induced early signs of acute lung injury with increased cellularity in the lung interstitium and rapid engorgement of alveolar septal vessels. Despite this in vivo activity, MWReg30 inhibited rather than stimulated platelet aggregation in vitro. MWReg30-binding to platelets led to phosphorylation of gpIIIa, but did not induce morphological signs of platelet activation. The MWReg30-induced reaction was abolished after treatment with MoAbs 2.4G2 to FcγRII/III and was absent in FcγRIII-deficient mice, clearly demonstrating the requirement for FcγRIII on involved leukocytes. Simultaneous administration of tumor necrosis factor exacerbated, whereas a tolerizing regimen of tumor necrosis factor or bacterial lipopolysaccharide completely prevented the reaction. These data suggest that platelet surface-deposited MWReg30-immune complexes lead to an acute Fc-mediated reaction with pulmonary congestion and life-threatening potential that could serve as an in vivo model of acute lung injury.

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