Enhancement of the endotoxin recognition pathway by ventilation with a large tidal volume in rabbits

2004 ◽  
Vol 286 (6) ◽  
pp. L1114-L1121 ◽  
Author(s):  
Kiyoshi Moriyama ◽  
Akitoshi Ishizaka ◽  
Morio Nakamura ◽  
Hiroshi Kubo ◽  
Toru Kotani ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Tidal Volume ◽  
Mechanical Stress ◽  
Clinical Outcomes ◽  
Alveolar Macrophages ◽  
Fold Increase ◽  
Large Tidal Volume ◽  
Tnf Α ◽  
Cd14 Mrna

Ventilation with a small tidal volume (Vt) is associated with better clinical outcomes than with a large Vt, particularly in critical settings, including acute lung injury. To determine whether Vt influences the lipopolysaccaharide (LPS) recognition pathway, we studied CD14 expression in rabbit lungs and the release of TNF-α by cultured alveolar macrophages after 240 min of ventilation with a large (20 ml/kg) vs. a small (5 ml/kg) Vt. We also applied small or large Vt to lungs instilled with 50 μg/kg of LPS. The alveolar macrophages collected after large Vt ventilation revealed a 20-fold increase in LPS-induced TNF-α release compared with those collected after small Vt ventilation, whereas TNF-α was undetectable without LPS stimulation. In animals ventilated with a large Vt, the expression of CD14 mRNA in whole lung homogenates and the expression of CD14 protein on alveolar macrophages, assessed by immunohistochemistry, were both significantly increased in the absence of LPS stimulation. A large Vt applied to LPS-instilled lungs increased the pulmonary albumin permeability and TNF-α release into the plasma. These results suggest that mechanical stress caused by a large Vt sensitizes the lungs to endotoxin, a phenomenon that may occur partially via the upregulation of CD14.

Effect of CO2 on LPS-induced cytokine responses in rat alveolar macrophages

2005 ◽  
Vol 289 (1) ◽  
pp. L96-L103 ◽  
Author(s):  
Carol J. Lang ◽  
Ping Dong ◽  
Emma K. Hosszu ◽  
Ian R. Doyle
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Metabolic Activity ◽  
Alveolar Macrophages ◽  
Culture Media ◽  
Cytokine Release ◽  
Cytokine Responses ◽  
Tnf Α ◽  
Effects Of Ph ◽  
The Media

Alveolar macrophages (AM) may be exposed to a range of CO2 and pH levels depending on their location in the alveoli and the health of the lung. Cytokines produced by AM contribute to inflammation in acute lung injury (ALI). Current ventilatory practices for the management of ALI favor low tidal volumes, which can give rise to increases in CO2 and changes in pH of the alveolar microenvironment. Here we examined the effect of CO2 on cytokine release from LPS-stimulated rat AM. AM were incubated for 1–4 h under different atmospheric gas mixtures ranging from 2.5–20% CO2. To distinguish between effects of pH and CO2, the culture media were also buffered to pH 7.2 with NaHCO3. Cell metabolic activity, but not cell viability, decreased and increased significantly after 4 h at 20 and 2.5% CO2, respectively. Increasing CO2 decreased TNF-α secretion but had no effect on lysate TNF-α. Buffering the media abated the effects of CO2 on TNF-α secretion. CO2 increased cytokine-induced neutrophil chemoattractant factor-1 secretion only when the pH was buffered to 7.2. Effects of CO2 on cytokine responses were reversible. In conclusion, the effects of CO2 on cytokine lysate levels and/or secretion in AM are cytokine specific and, depending on both the cytokine and the immediate microenvironment, may be beneficial or detrimental to ALI.

Toward the prevention of acute lung injury: Protocol-guided limitation of large tidal volume ventilation and inappropriate transfusion*

2007 ◽  
Vol 35 (7) ◽  
pp. 1660-1666 ◽  
Author(s):  
Murat Yilmaz ◽  
Mark T. Keegan ◽  
Remzi Iscimen ◽  
Bekele Afessa ◽  
Curtis F. Buck ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Tidal Volume ◽  
Large Tidal Volume ◽  
Volume Ventilation

Geranylgeranyl transferase regulates CXC chemokine formation in alveolar macrophages and neutrophil recruitment in septic lung injury

2013 ◽  
Vol 304 (4) ◽  
pp. L221-L229 ◽  
Author(s):  
Zirak Hasan ◽  
Milladur Rahman ◽  
Karzan Palani ◽  
Ingvar Syk ◽  
Bengt Jeppsson ◽  
...  
Keyword(s):  
Lung Injury ◽  
Alveolar Macrophages ◽  
Neutrophil Infiltration ◽  
Abdominal Sepsis ◽  
Neutrophil Recruitment ◽  
Chemokine Production ◽  
Tnf Α ◽  
Cxc Chemokine ◽  
Geranylgeranyl Transferase

Overwhelming accumulation of neutrophils is a significant component in septic lung damage, although the signaling mechanisms behind neutrophil infiltration in the lung remain elusive. In the present study, we hypothesized that geranylgeranylation might regulate the inflammatory response in abdominal sepsis. Male C57BL/6 mice received the geranylgeranyl transferase inhibitor, GGTI-2133, before cecal ligation and puncture (CLP). Bronchoalveolar lavage fluid and lung tissue were harvested for analysis of neutrophil infiltration, as well as edema and CXC chemokine formation. Blood was collected for analysis of Mac-1 on neutrophils and CD40L on platelets. Gene expression of CXC chemokines, tumor necrosis factor-α (TNF-α), and CCL2 chemokine was determined by quantitative RT-PCR in isolated alveolar macrophages. Administration of GGTI-2133 markedly decreased CLP-induced infiltration of neutrophils, edema, and tissue injury in the lung. CLP triggered clear-cut upregulation of Mac-1 on neutrophils. Inhibition of geranylgeranyl transferase reduced CLP-evoked upregulation of Mac-1 on neutrophils in vivo but had no effect on chemokine-induced expression of Mac-1 on isolated neutrophils in vitro. Notably, GGTI-2133 abolished CLP-induced formation of CXC chemokines, TNF-α, and CCL2 in alveolar macrophages in the lung. Geranylgeranyl transferase inhibition had no effect on sepsis-induced platelet shedding of CD40L. In addition, inhibition of geranylgeranyl transferase markedly decreased CXC chemokine-triggered neutrophil chemotaxis in vitro. Taken together, our findings suggest that geranylgeranyl transferase is an important regulator of CXC chemokine production and neutrophil recruitment in the lung. We conclude that inhibition of geranylgeranyl transferase might be a potent way to attenuate acute lung injury in abdominal sepsis.

Vanillin protects lipopolysaccharide-induced acute lung injury by inhibiting ERK1/2, p38 and NF-κB pathway

2019 ◽  
Vol 11 (16) ◽  
pp. 2081-2094 ◽  
Author(s):  
Tingting Guo ◽  
Zhenzhong Su ◽  
Qi Wang ◽  
Wei Hou ◽  
Junyao Li ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Western Blot ◽  
Lung Inflammation ◽  
Macrophage Activation ◽  
Myeloperoxidase Activity ◽  
Histopathological Changes ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
Inflammatory Effect

Aim: Thus far, the anti-inflammatory effect of vanillin in acute lung injury (ALI) has not been studied. This study aimed to investigate the effect of vanillin in lipopolysaccharide (LPS)-induced ALI. Results & methodology: Our study detected the anti-inflammatory effects of vanillin by ELISA and western blot, respectively. Pretreatment of mice with vanillin significantly attenuated LPS-stimulated lung histopathological changes, myeloperoxidase activity and expression levels of proinflammatory cytokines by inhibiting the phosphorylation activities of ERK1/2, p38, AKT and NF-κB p65. In addition, vanillin inhibited LPS-induced TNF-α and IL-6 expression in RAW264.7 cells via ERK1/2, p38 and NF-κB signaling. Conclusion: Vanillin can inhibit macrophage activation and lung inflammation, which suggests new insights for clinical treatment of ALI.

scholarly journals Phospholipase C-ε signaling mediates endothelial cell inflammation and barrier disruption in acute lung injury

2016 ◽  
Vol 311 (2) ◽  
pp. L517-L524 ◽  
Author(s):  
Kaiser M. Bijli ◽  
Fabeha Fazal ◽  
Spencer A. Slavin ◽  
Antony Leonard ◽  
Valerie Grose ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Phospholipase C ◽  
Phorbol Esters ◽  
Critical Determinant ◽  
Monocyte Chemoattractant Protein 1 ◽  
Barrier Disruption ◽  
Proinflammatory Mediators ◽  
Tnf Α

Phospholipase C-ε (PLC-ε) is a unique PLC isoform that can be regulated by multiple signaling inputs from both Ras family GTPases and heterotrimeric G proteins and has primary sites of expression in the heart and lung. Whereas the role of PLC-ε in cardiac function and pathology has been documented, its relevance in acute lung injury (ALI) is unclear. We used PLC-ε−/− mice to address the role of PLC-ε in regulating lung vascular inflammation and injury in an aerosolized bacterial LPS inhalation mouse model of ALI. PLC-ε−/− mice showed a marked decrease in LPS-induced proinflammatory mediators (ICAM-1, VCAM-1, TNF-α, IL-1β, IL-6, macrophage inflammatory protein 2, keratinocyte-derived cytokine, monocyte chemoattractant protein 1, and granulocyte-macrophage colony-stimulating factor), lung neutrophil infiltration and microvascular leakage, and loss of VE-cadherin compared with PLC-ε+/+ mice. These data identify PLC-ε as a critical determinant of proinflammatory and leaky phenotype of the lung. To test the possibility that PLC-ε activity in endothelial cells (EC) could contribute to ALI, we determined its role in EC inflammation and barrier disruption. RNAi knockdown of PLC-ε inhibited NF-κB activity in response to diverse proinflammatory stimuli, thrombin, LPS, TNF-α, and the nonreceptor agonist phorbol 13-myristate 12-acetate (phorbol esters) in EC. Depletion of PLC-ε also inhibited thrombin-induced expression of NF-κB target gene, VCAM-1. Importantly, PLC-ε knockdown also protected against thrombin-induced EC barrier disruption by inhibiting the loss of VE-cadherin at adherens junctions and formation of actin stress fibers. These data identify PLC-ε as a novel regulator of EC inflammation and permeability and show a hitherto unknown role of PLC-ε in the pathogenesis of ALI.

INFLUENCE OF DEPLETION OF ALVEOLAR MACROPHAGES ON APOPTOSIS INCANDIDA-INDUCED ACUTE LUNG INJURY

2005 ◽  
Vol 31 (3) ◽  
pp. 307-321 ◽  
Author(s):  
Yoshizumi Takemura ◽  
Yoshinobu Iwasaki ◽  
Kazuhiro Nagata ◽  
Ichiro Yokomura ◽  
Sou Tando ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Alveolar Macrophages
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