scholarly journals A Peptide Inhibitor of Peroxiredoxin 6 Phospholipase A2 Activity Significantly Protects against Lung Injury in a Mouse Model of Ventilator Induced Lung Injury (VILI)

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 925
Author(s):  
Aron B. Fisher ◽  
Chandra Dodia ◽  
Shampa Chatterjee
Keyword(s):  
Lung Injury ◽  
Tidal Volume ◽  
Thiobarbituric Acid ◽  
Lavage Fluid ◽  
Lung Damage ◽  
Protein Carbonyls ◽  
Lung Edema ◽  
Peroxiredoxin 6 ◽  
Ventilator Induced Lung Injury ◽  
Volume Ventilation

Ventilator induced lung injury (VILI) is a lung injury syndrome associated with mechanical ventilation, most frequently for treatment of Acute Lung Injury (ALI), and generally secondary to the use of greater than physiologic tidal volumes. To reproduce this syndrome experimentally, C57Bl/6 mice were intubated and ventilated with low (4 mL/Kg body weight) or high (12 mL/Kg) tidal volume for 6 h. Lung parameters with low volume ventilation were unchanged from non-ventilated (control) mice. High tidal volume ventilation resulted in marked lung injury with increased neutrophils in the bronchoalveolar lavage fluid (BALF) indicating lung inflammation, increase in both protein in BALF and lung dry/wet weight indicating lung edema, increased lung thiobarbituric acid reactive substances (TBARS), and 8-isoprostanes indicating lung lipid peroxidation, and increased lung protein carbonyls indicating protein oxidation. Either intratracheal or intravenous pretreatment of mice with a 9 amino acid peptide called peroxiredoxin 6 inhibitor peptide-2 (PIP-2) significantly reduced all parameters of lung injury by ~50–80%. PIP-2 inhibits NADPH oxidase type 2 (NOX2) activation. We propose that PIP-2 does not affect the mechanically induced lung damage component of VILI but does significantly reduce the secondary inflammatory component.

A Metabolomic Approach to the Pathogenesis of Ventilator-induced Lung Injury

2014 ◽  
Vol 120 (3) ◽  
pp. 694-702 ◽  
Author(s):  
José L. Izquierdo-García ◽  
Shama Naz ◽  
Nicolás Nin ◽  
Yeny Rojas ◽  
Marcela Erazo ◽  
...  
Keyword(s):  
Lung Injury ◽  
Bronchoalveolar Lavage ◽  
Tidal Volume ◽  
Lung Tissue ◽  
Metabolic Profiling ◽  
Metabolic Profile ◽  
Bronchoalveolar Lavage Fluid ◽  
Lavage Fluid ◽  
Positive End Expiratory Pressure ◽  
Ventilator Induced Lung Injury

Abstract Background: Global metabolic profiling using quantitative nuclear magnetic resonance spectroscopy (MRS) and mass spectrometry (MS) is useful for biomarker discovery. The objective of this study was to discover biomarkers of acute lung injury induced by mechanical ventilation (ventilator-induced lung injury [VILI]), by using MRS and MS. Methods: Male Sprague–Dawley rats were subjected to two ventilatory strategies for 2.5 h: tidal volume 9 ml/kg, positive end-expiratory pressure 5 cm H2O (control, n = 14); and tidal volume 25 ml/kg and positive end-expiratory pressure 0 cm H2O (VILI, n = 10). Lung tissue, bronchoalveolar lavage fluid, and serum spectra were obtained by high-resolution magic angle spinning and 1H-MRS. Serum spectra were acquired by high-performance liquid chromatography coupled to quadupole-time of flight MS. Principal component and partial least squares analyses were performed. Results: Metabolic profiling discriminated characteristics between control and VILI animals. As compared with the controls, animals with VILI showed by MRS higher concentrations of lactate and lower concentration of glucose and glycine in lung tissue, accompanied by increased levels of glucose, lactate, acetate, 3-hydroxybutyrate, and creatine in bronchoalveolar lavage fluid. In serum, increased levels of phosphatidylcholine, oleamide, sphinganine, hexadecenal and lysine, and decreased levels of lyso-phosphatidylcholine and sphingosine were identified by MS. Conclusions: This pilot study suggests that VILI is characterized by a particular metabolic profile that can be identified by MRS and MS. The metabolic profile, though preliminary and pending confirmation in larger data sets, suggests alterations in energy and membrane lipids. SUPPLEMENTAL DIGITAL CONTENT IS AVAILABLE IN THE TEXT

scholarly journals NADPH Oxidase 4 Signaling in a Ventilator-induced Lung Injury Mouse Model

2021 ◽  
Author(s):  
Sang Hoon Lee ◽  
Mi Hwa Shin ◽  
Ah Young Leem ◽  
Su Hwan Lee ◽  
Kyung Soo Chung ◽  
...  
Keyword(s):  
Lung Injury ◽  
Lavage Fluid ◽  
Lung Damage ◽  
Control Group ◽  
Group 4 ◽  
Ventilator Induced Lung Injury ◽  
Cell Counts ◽  
Group 5 ◽  
Group 2

Abstract For patients with acute respiratory distress syndrome, a ventilator is essential to supply oxygen to tissues, but it may also cause lung damage. We investigated the role of NOX4 in a ventilator-induced lung injury (VILI) model.Wild-type (WT) male C57BL/6J mice and NOX4 knockout (KO) male mice were divided into five groups: (1) control group; (2) high tidal ventilation (HTV) group: WT mice + HTV; (3) NOX4 KO group; (4) NOX4 KO with HTV group; (5) NOX4 inhibitor group: WT mice + HTV + NOX4 inhibitor. In addition, the relationship between EphA2 (which is related to lung injury) and NOX4 was investigated using EphA2 KO mice, and NOX4 levels in the bronchoalveolar lavage fluid (BALF) of 38 patients with pneumonia were examined.In the NOX4 inhibitor group, cell counts and protein concentrations from BALF were significantly lower than those in the HTV group (both, p<0.001). In the NOX4 KO group and the NOX4 inhibitor group, EphA2 levels were significantly lower than those in the HTV group (p<0.001). NOX4 levels were significantly higher in patients with pneumonia and patients who received ventilator treatment in the ICU.In the VILI model, it may be possible to block VILI using NOX4 antibodies.

scholarly journals Rap1 mediates protective effects of iloprost against ventilator-induced lung injury

2009 ◽  
Vol 107 (6) ◽  
pp. 1900-1910 ◽  
Author(s):  
Anna A. Birukova ◽  
Panfeng Fu ◽  
Junjie Xing ◽  
Konstantin G. Birukov
Keyword(s):  
Lung Injury ◽  
Bronchoalveolar Lavage ◽  
Tidal Volume ◽  
Evans Blue ◽  
High Tidal Volume ◽  
Protective Effects ◽  
Ventilator Induced Lung Injury ◽  
High Tidal Volume Ventilation ◽  
Volume Ventilation

Prostaglandin I2 (PGI2) has been shown to attenuate vascular constriction, hyperpermeability, inflammation, and acute lung injury. However, molecular mechanisms of PGI2 protective effects on pulmonary endothelial cells (EC) are not well understood. We tested a role of cAMP-activated Epac-Rap1 pathway in the barrier protective effects of PGI2 analog iloprost in the murine model of ventilator-induced lung injury. Mice were treated with iloprost (2 μg/kg) after onset of high tidal volume ventilation (30 ml/kg, 4 h). Bronchoalveolar lavage, histological analysis, and measurements of Evans blue accumulation were performed. In vitro, microvascular EC barrier function was assessed by morphological analysis of agonist-induced gap formation and monitoring of Rho pathway activation and EC permeability. Iloprost reduced bronchoalveolar lavage protein content, neutrophil accumulation, capillary filtration coefficient, and Evans blue albumin extravasation caused by high tidal volume ventilation. Small-interfering RNA-based Rap1 knockdown inhibited protective effects of iloprost. In vitro, iloprost increased barrier properties of lung microvascular endothelium and alleviated thrombin-induced EC barrier disruption. In line with in vivo results, Rap1 depletion attenuated protective effects of iloprost in the thrombin model of EC permeability. These data describe for the first time protective effects for Rap1-dependent signaling against ventilator-induced lung injury and pulmonary endothelial barrier dysfunction.

scholarly journals Activation of calpains mediates early lung neutrophilic inflammation in ventilator-induced lung injury

2012 ◽  
Vol 302 (4) ◽  
pp. L370-L379 ◽  
Author(s):  
Dejie Liu ◽  
Zhibo Yan ◽  
Richard D. Minshall ◽  
David E. Schwartz ◽  
Yuguo Chen ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Lung Injury ◽  
Tidal Volume ◽  
Lung Inflammation ◽  
Inflammatory Responses ◽  
Neutrophil Recruitment ◽  
Calpain Activation ◽  
Ventilator Induced Lung Injury ◽  
Volume Ventilation ◽  
Calpain 2

Lung inflammatory responses in the absence of infection are considered to be one of primary mechanisms of ventilator-induced lung injury. Here, we determined the role of calpain in the pathogenesis of lung inflammation attributable to mechanical ventilation. Male C57BL/6J mice were subjected to high (28 ml/kg) tidal volume ventilation for 2 h in the absence and presence of calpain inhibitor I (10 mg/kg). To address the isoform-specific functions of calpain 1 and calpain 2 during mechanical ventilation, we utilized a liposome-based delivery system to introduce small interfering RNAs targeting each isoform in pulmonary vasculature in vivo. Mechanical ventilation with high tidal volume induced rapid (within minutes) and persistent calpain activation and lung inflammation as evidenced by neutrophil recruitment, production of TNF-α and IL-6, pulmonary vascular hyperpermeability, and lung edema formation. Pharmaceutical calpain inhibition significantly attenuated these inflammatory responses caused by lung hyperinflation. Depletion of calpain 1 or calpain 2 had a protective effect against ventilator-induced lung inflammatory responses. Inhibition of calpain activity by means of siRNA silencing or pharmacological inhibition also reduced endothelial nitric oxide (NO) synthase (NOS-3)-mediated NO production and subsequent ICAM-1 phosphorylation following high tidal volume ventilation. These results suggest that calpain activation mediates early lung inflammation during ventilator-induced lung injury via NOS-3/NO-dependent ICAM-1 phosphorylation and neutrophil recruitment. Inhibition of calpain activation may therefore provide a novel and promising strategy for the prevention and treatment of ventilator-induced lung injury.

Neutrophil Stimulation with Granulocyte Colony-stimulating Factor Worsens Ventilator-induced Lung Injury and Mortality in Rats

2005 ◽  
Vol 103 (5) ◽  
pp. 996-1005 ◽  
Author(s):  
Waheedullah Karzai ◽  
Xizhong Cui ◽  
Norbert Heinicke ◽  
Christian Niemann ◽  
Eric P. Gerstenberger ◽  
...  
Keyword(s):  
Lung Injury ◽  
Tidal Volume ◽  
Arterial Oxygen ◽  
Placebo Control ◽  
Lung Edema ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Ventilator Induced Lung Injury ◽  
Lung Dysfunction ◽  
Stimulating Factor

Background Based on the association between the neutrophil and ventilator-induced lung injury, the authors hypothesized that neutrophil inhibition with fucoidin would be beneficial and stimulation with granulocyte colony-stimulating factor (G-CSF) would be harmful in a rat model of lethal ventilator-induced lung injury. Methods Animals (n = 111) were randomly assigned to be pretreated with fucoidin, G-CSF, or placebo (control) before 4 h of low-tidal-volume (10 ml/kg) or high-tidal-volume (40 ml/kg) mechanical ventilation. Results All low-volume animals survived. With high volumes, compared with controls, fucoidin did not improve survival (3 of 20 control animals and 5 of 20 fucoidin animals died; P = 0.51) but G-CSF significantly worsened it (18 of 22 animals died; P &lt; 0.001). Circulating neutrophils were increased early with G-CSF and late with fucoidin with low and high tidal volumes (P &lt; 0.05 for each treatment and tidal volume). Fucoidin decreased lung neutrophils, but these were only significant with high tidal volumes, whereas G-CSF increased lung neutrophils but only significantly with low tidal volumes (P &lt; or = 0.01 for each). Fucoidin did not alter any cardiopulmonary measure significantly. Compared with control, G-CSF increased airway pressures with high tidal volumes and worsened lung edema and arterial oxygen with both tidal volumes (P &lt; 0.05 for each). Conclusions In this model, neutrophil stimulation by G-CSF increased lung dysfunction and with high tidal volumes worsened survival rates. Extrapolated clinically, neutrophil stimulation either by agents such as G-CSF or conditions such as sepsis may aggravate ventilator-induced lung injury.

scholarly journals NADPH Oxidase 4 Signaling in a Ventilator-Induced Lung Injury Mouse Model

2020 ◽  
Author(s):  
Sang Hoon Lee ◽  
Mi Hwa Shin ◽  
Ah Young Leem ◽  
Su Hwan Lee ◽  
Kyung Soo Chung ◽  
...  
Keyword(s):  
Lung Injury ◽  
Lavage Fluid ◽  
Lung Damage ◽  
Control Group ◽  
Nadph Oxidase 4 ◽  
Ventilator Induced Lung Injury ◽  
Oxygen Fraction ◽  
Cell Counts ◽  
The Relationship

Abstract BackgroundFor patients with acute respiratory distress syndrome (ARDS), a ventilator is essential to supply oxygen to tissues, but it may also cause lung damage. In this study, we investigated the role of NOX4 in lung injury using NOX4 knockout (KO) mice and NOX4 inhibitors in a ventilator-induced lung injury (VILI) model.MethodsWild-type male C57BL/6J mice and NOX4 KO male mice were divided into five groups: (1) control group: wild-type (WT) mice + non-ventilator; (2) high tidal ventilation (HTV) group: WT mice + HTV; (3) NOX4 KO group: NOX4 KO + non-ventilator; (4) NOX4 KO with HTV group: NOX4 KO mice + HTV; (5) NOX4 inhibitor group: WT mice + HTV + post-treatment (anti-GKT 137831 inhibitor). In the VILI model, the supine position was maintained at 24 mL/kg volume, 0 cm H2O PEEP, 100/min respiratory rate, and 0.21 inspired oxygen fraction. In the NOX4 inhibitor group, 50 μL anti-GKT 137831 inhibitor was injected intraperitoneally, 2 h after ventilator use. After 5 h of HTV, mice in the ventilator group were euthanized, and their lung tissues were obtained for further analysis. In addition, the relationship between EphA2 (which is related to lung injury) and NOX4 was investigated using EphA2 KO mice, and NOX4 levels in the bronchoalveolar lavage fluid (BALF) of 38 patients with pneumonia were examined.ResultsCell counts from BALFs were significantly lower (p<0.01) in the NOX4 KO with HTV group compared to that in the HTV group. In the NOX4 inhibitor group, cell counts and protein concentrations were significantly lower than those in the HTV group (both, p<0.001). In the NOX4 KO mouse group and the NOX4 inhibitor group, EphA2 levels were significantly lower than those in the HTV group (both, p<0.001). In patients with respiratory disease, NOX4 levels were significantly higher in patients with pneumonia and patients who received ventilator treatment in the intensive care unit.ConclusionsIn the VILI model, NOX4 expression is significantly associated with Eph-ephrin signaling. It may be possible to block VILI using NOX4 antibodies.

TLR4 is required for macrophage efferocytosis during resolution of ventilator-induced lung injury

2021 ◽  
Vol 321 (4) ◽  
pp. L787-L801
Author(s):  
Kai Su ◽  
Lulong Bo ◽  
Chunling Jiang ◽  
Xiaoming Deng ◽  
You-Yang Zhao ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Lung Injury ◽  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Molecular Mechanisms ◽  
Tissue Injury ◽  
Lung Damage ◽  
Lung Edema ◽  
Apoptotic Cells ◽  
Ventilator Induced Lung Injury

Mechanical ventilation is a life-sustaining therapy for patients with respiratory failure but can cause further lung damage known as ventilator-induced lung injury (VILI). However, the intrinsic molecular mechanisms underlying recovery of VILI remain unknown. Phagocytosis of apoptotic cells (also known as efferocytosis) is a key mechanism orchestrating successful resolution of inflammation. Here we show the positive regulation of macrophage Toll-like receptor (TLR) 4 in efferocytosis and resolution of VILI. Mice were depleted of alveolar macrophages and then subjected to injurious ventilation (tidal volume, 20 mL/kg) for 4 h. On day 1 after mechanical ventilation, Tlr4+/+ or Tlr4−/− bone marrow-derived macrophages (BMDMs) were intratracheally administered to alveolar macrophage-depleted mice. We observed that mice depleted of alveolar macrophages exhibited defective resolution of neutrophilic inflammation, exuded protein, lung edema, and lung tissue injury after ventilation, whereas these delayed responses were reversed by administration of Tlr4+/+ BMDMs. Importantly, these proresolving effects by Tlr4+/+ BMDMs were abolished in mice receiving Tlr4−/− BMDMs. The number of macrophages containing apoptotic cells or bodies in bronchoalveolar lavage fluid was much less in mice receiving Tlr4−/− BMDMs than that in those receiving Tlr4+/+ BMDMs. Macrophage TLR4 deletion facilitated a disintegrin and metalloprotease 17 maturation and enhanced Mer cleavage in response to mechanical ventilation. Heat shock protein 70 dramatically increased Mer tyrosine kinase surface expression, phagocytosis of apoptotic neutrophils, and rescued the inflammatory phenotype in alveolar macrophage-depleted mice receiving Tlr4+/+ BMDMs, but not Tlr4−/− BMDMs. Our results suggest that macrophage TLR4 promotes resolution of VILI via modulation of Mer-mediated efferocytosis.

Congenital NOS2 deficiency prevents impairment of hypoxic pulmonary vasoconstriction in murine ventilator-induced lung injury

2007 ◽  
Vol 293 (5) ◽  
pp. L1300-L1305 ◽  
Author(s):  
Rong Liu ◽  
Yukako Hotta ◽  
Amanda R. Graveline ◽  
Oleg V. Evgenov ◽  
Emmanuel S. Buys ◽  
...  
Keyword(s):  
Lung Injury ◽  
Tidal Volume ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Left Lung ◽  
Arterial Oxygen Tension ◽  
Arterial Oxygen ◽  
Lung Edema ◽  
Wild Type ◽  
Ventilator Induced Lung Injury ◽  
Pulmonary Vasoconstriction

Hypoxic pulmonary vasoconstriction (HPV) preserves systemic arterial oxygenation during lung injury by diverting blood flow away from poorly ventilated lung regions. Ventilator-induced lung injury (VILI) is characterized by pulmonary inflammation, lung edema, and impaired HPV leading to systemic hypoxemia. Studying mice congenitally deficient in inducible nitric oxide synthase (NOS2) and wild-type mice treated with a selective NOS2 inhibitor, l- N6-(1-iminoethyl)lysine (l-NIL), we investigated the contribution of NOS2 to the impairment of HPV in anesthetized mice subjected to 6 h of either high tidal volume (HVT) or low tidal volume (LVT) ventilation. HPV was estimated by measuring the changes of left lung pulmonary vascular resistance (LPVR) in response to left mainstem bronchus occlusion (LMBO). LMBO increased the LPVR similarly in wild-type, NOS2−/−, and wild-type mice treated with l-NIL 30 min before commencing 6 h of LVT ventilation (96% ± 30%, 103% ± 33%, and 80% ± 16%, respectively, means ± SD). HPV was impaired in wild-type mice subjected to 6 h of HVT ventilation (23% ± 16%). In contrast, HPV was preserved after 6 h of HVT ventilation in NOS2−/− and wild-type mice treated with l-NIL either 30 min before or 6 h after commencing HVT ventilation (66% ± 22%, 82% ± 29%, and 85% ± 16%, respectively). After 6 h of HVT ventilation and LMBO, systemic arterial oxygen tension was higher in NOS2−/− than in wild-type mice (192 ± 11 vs. 171 ± 17 mmHg; P < 0.05). We conclude that either congenital NOS2 deficiency or selective inhibition of NOS2 protects mice from the impairment of HPV occurring after 6 h of HVT ventilation.

scholarly journals Reduction of Lung Inflammation, Oxidative Stress and Apoptosis by the PDE4 Inhibitor Roflumilast in Experimental Model of Acute Lung Injury

2018 ◽  
pp. S645-S654 ◽  
Author(s):  
P. KOSUTOVA ◽  
P. MIKOLKA ◽  
M. KOLOMAZNIK ◽  
S. BALENTOVA ◽  
M. ADAMKOV ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Cell Apoptosis ◽  
White Blood Cells ◽  
Thiobarbituric Acid ◽  
Lavage Fluid ◽  
Pde4 Inhibitor ◽  
Lung Edema ◽  
Edema Formation ◽  
Differential Counts

Damage of alveolar-capillary barrier, inflammation, oxidative injury, and lung cell apoptosis represent the key features of acute lung injury (ALI). This study evaluated if selective phosphodiesterase (PDE)-4 inhibitor roflumilast can reduce the mentioned changes in lavage-induced model of ALI. Rabbits with ALI were divided into 2 groups: ALI without therapy (A group) and ALI treated with roflumilast i.v. (1 mg/kg; A+R group). One group of healthy animals without ALI served as ventilated controls (C group). All animals were oxygen-ventilated for further 4 h. At the end of experiment, total and differential counts of cells in bronchoalveolar lavage fluid (BALF) and total and differential counts of white blood cells were estimated. Lung edema formation was assessed from determination of protein content in BALF. Pro-inflammatory cytokines (TNFα, IL-6 and IL-8) and markers of oxidation (3-nitrotyrosine, thiobarbituric-acid reactive substances) were detected in the lung tissue and plasma. Apoptosis of lung cells was investigated immunohistochemically. Treatment with roflumilast reduced leak of cells, particularly of neutrophils, into the lung, decreased concentrations of cytokines and oxidative products in the lung and plasma, and reduced lung cell apoptosis and edema formation. Concluding, PDE4 inhibitor roflumilast showed potent anti-inflammatory actions in this model of ALI.

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