Transfusion-related acute lung injury: advances in understanding the role of proinflammatory mediators in its genesis

2013 ◽  
Vol 6 (3) ◽  
pp. 265-276 ◽  
Author(s):  
F Bernadette West ◽  
Christopher C Silliman
2016 ◽  
Vol 311 (2) ◽  
pp. L517-L524 ◽  
Author(s):  
Kaiser M. Bijli ◽  
Fabeha Fazal ◽  
Spencer A. Slavin ◽  
Antony Leonard ◽  
Valerie Grose ◽  
...  

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.


2018 ◽  
Vol 314 (3) ◽  
pp. L388-L396 ◽  
Author(s):  
Spencer A. Slavin ◽  
Antony Leonard ◽  
Valerie Grose ◽  
Fabeha Fazal ◽  
Arshad Rahman

Autophagy is an evolutionarily conserved cellular process that facilitates the continuous recycling of intracellular components (organelles and proteins) and provides an alternative source of energy when nutrients are scarce. Recent studies have implicated autophagy in many disorders, including pulmonary diseases. However, the role of autophagy in endothelial cell (EC) barrier dysfunction and its relevance in the context of acute lung injury (ALI) remain uncertain. Here, we provide evidence that autophagy is a critical component of EC barrier disruption in ALI. Using an aerosolized bacterial lipopolysaccharide (LPS) inhalation mouse model of ALI, we found that administration of the autophagy inhibitor 3-methyladenine (3-MA), either prophylactically or therapeutically, markedly reduced lung vascular leakage and tissue edema. 3-MA was also effective in reducing the levels of proinflammatory mediators and lung neutrophil sequestration induced by LPS. To test the possibility that autophagy in EC could contribute to lung vascular injury, we addressed its role in the mechanism of EC barrier disruption. Knockdown of ATG5, an essential regulator of autophagy, attenuated thrombin-induced EC barrier disruption, confirming the involvement of autophagy in the response. Similarly, exposure of cells to 3-MA, either before or after thrombin, protected against EC barrier dysfunction by inhibiting the cleavage and loss of vascular endothelial cadherin at adherens junctions, as well as formation of actin stress fibers. 3-MA also reversed LPS-induced EC barrier disruption. Together, these data imply a role of autophagy in lung vascular injury and reveal the protective and therapeutic utility of 3-MA against ALI.


2019 ◽  
Vol 39 (6) ◽  
Author(s):  
Tao Qiu ◽  
Jiangqiao Zhou ◽  
Tianyu Wang ◽  
Zhongbao Chen ◽  
Xiaoxiong Ma ◽  
...  

AbstractAcute lung injury (ALI) is an acute inflammatory disease. Leukocyte immunoglobulin-like receptor B4 (LILRB4) is an immunoreceptor tyrosine-based inhibitory motif (ITIM)-bearing inhibitory receptor that is implicated in various pathological processes. However, the function of LILRB4 in ALI remains largely unknown. The aim of the present study was to explore the role of LILRB4 in ALI. LILRB4 knockout mice (LILRB4 KO) were used to construct a model of ALI. Bone marrow cell transplantation was used to identify the cell source of the LILRB4 deficiency-aggravated inflammatory response in ALI. The effect on ALI was analyzed by pathological and molecular analyses. Our results indicated that LILRB4 KO exacerbated ALI triggered by LPS. Additionally, LILRB4 deficiency can enhance lung inflammation. According to the results of our bone marrow transplant model, LILRB4 regulates the occurrence and development of ALI by bone marrow-derived macrophages (BMDMs) rather than by stromal cells in the lung. The observed inflammation was mainly due to BMDM-induced NF-κB signaling. In conclusion, our study demonstrates that LILRB4 deficiency plays a detrimental role in ALI-associated BMDM activation by prompting the NF-κB signal pathway.


2004 ◽  
Vol 287 (2) ◽  
pp. L448-L453 ◽  
Author(s):  
Thomas Geiser ◽  
Masanobu Ishigaki ◽  
Coretta van Leer ◽  
Michael A. Matthay ◽  
V. Courtney Broaddus

Reactive oxygen species (ROS) are released into the alveolar space and contribute to alveolar epithelial damage in patients with acute lung injury. However, the role of ROS in alveolar repair is not known. We studied the effect of ROS in our in vitro wound healing model using either human A549 alveolar epithelial cells or primary distal lung epithelial cells. We found that H2O2 inhibited alveolar epithelial repair in a concentration-dependent manner. At similar concentrations, H2O2 also induced apoptosis, an effect seen particularly at the edge of the wound, leading us to hypothesize that apoptosis contributes to H2O2-induced inhibition of wound repair. To learn the role of apoptosis, we blocked caspases with the pan-caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp (zVAD). In the presence of H2O2, zVAD inhibited apoptosis, particularly at the wound edge and, most importantly, maintained alveolar epithelial wound repair. In H2O2-exposed cells, zVAD also maintained cell viability as judged by improved cell spreading and/or migration at the wound edge and by a more normal mitochondrial potential difference compared with cells not treated with zVAD. In conclusion, H2O2 inhibits alveolar epithelial wound repair in large part by induction of apoptosis. Inhibition of apoptosis can maintain wound repair and cell viability in the face of ROS. Inhibiting apoptosis may be a promising new approach to improve repair of the alveolar epithelium in patients with acute lung injury.


2017 ◽  
Vol 34 ◽  
pp. 181-188 ◽  
Author(s):  
Heung Joo Yuk ◽  
Jae Won Lee ◽  
Hyun Ah Park ◽  
Ok-Kyoung Kwon ◽  
Kyeong-Hwa Seo ◽  
...  

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