scholarly journals O3‐6: The Pulmonary Endothelium Plays a Critical Role in the Fibrotic Response to Lung Injury through S1PR1 and ROCK Mediated Cytoskeletal Rearrangements

Respirology ◽  
2021 ◽  
Vol 26 (S3) ◽  
pp. 12-12
2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Ying Jiang ◽  
Zhen Zhou ◽  
Qing-tao Meng ◽  
Qian Sun ◽  
Wating Su ◽  
...  

Objective. Intestinal ischemia reperfusion (II/R) injury plays a critical role in remote organ dysfunction, such as lung injury, which is associated with nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. In the present study, we tested whether ginsenoside Rb1 attenuated II/R induced lung injury by Nrf2/HO-1 pathway.Methods. II/R injury was induced in male C57BL/6J mice by 45 min of superior mesenteric artery (SMA) occlusion followed by 2 hours of reperfusion. Ginsenoside Rb1 was administrated prior to reperfusion with or without ATRA (all-transretinoic acid, the inhibitor of Nrf2/ARE signaling pathway) administration before II/R.Results. II/R induced lung histological injury, which is accompanied with increased levels of malondialdehyde (MDA), interleukin- (IL-) 6, and tumor necrosis factor- (TNF-)αbut decreased levels of superoxide dismutase (SOD) and IL-10 in the lung tissues. Ginsenoside Rb1 reduced lung histological injury and the levels of TNF-αand MDA, as well as wet/dry weight ratio. Interestingly, the increased Nrf2 and HO-1 expression induced by II/R in the lung tissues was promoted by ginsenoside Rb1 treatment. All these changes could be inhibited or prevented by ATRA.Conclusion. Ginsenoside Rb1 is capable of ameliorating II/R induced lung injuries by activating Nrf2/HO-1 pathway.


2006 ◽  
Vol 291 (5) ◽  
pp. L1050-L1058 ◽  
Author(s):  
Sandra Perkowski ◽  
Arnaud Scherpereel ◽  
Juan-Carlos Murciano ◽  
Evguenia Arguiri ◽  
Charalambos C. Solomides ◽  
...  

The objective of this study was to quantitatively assess changes in cell adhesion molecule (CAM) expression on the pulmonary endothelial surface during hyperoxia and to assess the functional significance of those changes on cellular trafficking and development of oxygen-induced lung injury. Mice were placed in >95% O2 for 0–72 h, and pulmonary injury and neutrophil (PMN) sequestration were assessed. Specific pulmonary CAM expression was quantified with a dual-radiolabeled MAb technique. To test the role of CAMs in PMN trafficking during hyperoxia, blocking MAbs to murine P-selectin, ICAM-1, or platelet-endothelial cell adhesion molecule-1 (PECAM-1) were injected in wild-type mice. Mice genetically deficient in these CAMs and PMN-depleted mice were also evaluated. PMN sequestration occurred within 8 h of hyperoxia, although alveolar emigration occurred later (between 48 and 72 h), coincident with rapid escalation of the lung injury. Hyperoxia significantly increased pulmonary uptake of radiolabeled antibodies to P-selectin, ICAM-1, and PECAM-1, reflecting an increase in their level on pulmonary endothelium and possibly sequestered blood cells. Although both anti-PECAM-1 and anti-ICAM-1 antibodies suppressed PMN alveolar influx in wild-type mice, only mice genetically deficient in PECAM-1 showed PMN influx suppression. Neither CAM blockade, nor genetic deficiency, nor PMN depletion attenuated lung injury. We conclude that early pulmonary PMN retention during hyperoxia is not temporally associated with an increase in endothelial CAMs; however, subsequent PMN emigration into the alveolar space may be supported by PECAM-1 and ICAM-1. Blocking PMN recruitment did not prevent lung injury, supporting dissociation between PMN infiltration and lung injury during hyperoxia in mice.


Thorax ◽  
2021 ◽  
pp. thoraxjnl-2020-216469
Author(s):  
Alison W Ha ◽  
Tao Bai ◽  
David L Ebenezer ◽  
Tanvi Sethi ◽  
Tara Sudhadevi ◽  
...  

IntroductionNeonatal lung injury as a consequence of hyperoxia (HO) therapy and ventilator care contribute to the development of bronchopulmonary dysplasia (BPD). Increased expression and activity of lysyl oxidase (LOX), a key enzyme that cross-links collagen, was associated with increased sphingosine kinase 1 (SPHK1) in human BPD. We, therefore, examined closely the link between LOX and SPHK1 in BPD.MethodThe enzyme expression of SPHK1 and LOX were assessed in lung tissues of human BPD using immunohistochemistry and quantified (Halo). In vivo studies were based on Sphk1−/− and matched wild type (WT) neonatal mice exposed to HO while treated with PF543, an inhibitor of SPHK1. In vitro mechanistic studies used human lung microvascular endothelial cells (HLMVECs).ResultsBoth SPHK1 and LOX expressions were increased in lungs of patients with BPD. Tracheal aspirates from patients with BPD had increased LOX, correlating with sphingosine-1-phosphate (S1P) levels. HO-induced increase of LOX in lungs were attenuated in both Sphk1−/− and PF543-treated WT mice, accompanied by reduced collagen staining (sirius red). PF543 reduced LOX activity in both bronchoalveolar lavage fluid and supernatant of HLMVECs following HO. In silico analysis revealed STAT3 as a potential transcriptional regulator of LOX. In HLMVECs, following HO, ChIP assay confirmed increased STAT3 binding to LOX promoter. SPHK1 inhibition reduced phosphorylation of STAT3. Antibody to S1P and siRNA against SPNS2, S1P receptor 1 (S1P1) and STAT3 reduced LOX expression.ConclusionHO-induced SPHK1/S1P signalling axis plays a critical role in transcriptional regulation of LOX expression via SPNS2, S1P1 and STAT3 in lung endothelium.


2016 ◽  
Vol 311 (2) ◽  
pp. L208-L218 ◽  
Author(s):  
Dean O. Kuethe ◽  
Piotr T. Filipczak ◽  
Jeremy M. Hix ◽  
Andrew P. Gigliotti ◽  
Raúl San José Estépar ◽  
...  

Animal models play a critical role in the study of acute respiratory distress syndrome (ARDS) and ventilator-induced lung injury (VILI). One limitation has been the lack of a suitable method for serial assessment of acute lung injury (ALI) in vivo. In this study, we demonstrate the sensitivity of magnetic resonance imaging (MRI) to assess ALI in real time in rat models of VILI. Sprague-Dawley rats were untreated or treated with intratracheal lipopolysaccharide or PBS. After 48 h, animals were mechanically ventilated for up to 15 h to induce VILI. Free induction decay (FID)-projection images were made hourly. Image data were collected continuously for 30 min and divided into 13 phases of the ventilatory cycle to make cinematic images. Interleaved measurements of respiratory mechanics were performed using a flexiVent ventilator. The degree of lung infiltration was quantified in serial images throughout the progression or resolution of VILI. MRI detected VILI significantly earlier (3.8 ± 1.6 h) than it was detected by altered lung mechanics (9.5 ± 3.9 h, P = 0.0156). Animals with VILI had a significant increase in the Index of Infiltration ( P = 0.0027), and early regional lung infiltrates detected by MRI correlated with edema and inflammatory lung injury on histopathology. We were also able to visualize and quantify regression of VILI in real time upon institution of protective mechanical ventilation. Magnetic resonance lung imaging can be utilized to investigate mechanisms underlying the development and propagation of ALI, and to test the therapeutic effects of new treatments and ventilator strategies on the resolution of ALI.


Blood ◽  
2010 ◽  
Vol 116 (16) ◽  
pp. 3073-3079 ◽  
Author(s):  
Yoke Lin Fung ◽  
Michael Kim ◽  
Arata Tabuchi ◽  
Rukhsana Aslam ◽  
Edwin R. Speck ◽  
...  

Abstract Transfusion-related acute lung injury (TRALI) is a serious complication of transfusion and has been ranked as one of the leading causes of transfusion-related fatalities. Nonetheless, many details of the immunopathogenesis of TRALI, particularly with respect to recipient factors are unknown. We used a murine model of antibody-mediated TRALI in an attempt to understand the role that recipient lymphocytes might play in TRALI reactions. Intravenous injection of an IgG2a antimurine major histocompatibility complex class I antibody (34-1-2s) into BALB/c mice induced moderate hypothermia and pulmonary granulocyte accumulation but no pulmonary edema nor mortality. In contrast, 34-1-2s injections into mice with severe combined immunodeficiency caused severe hypothermia, severe pulmonary edema, and approximately 40% mortality indicating a critical role for T and B lymphocytes in suppressing TRALI reactions. Adoptive transfer of purified CD8+ T lymphocytes or CD4+ T cells but not CD19+ B cells into the severe combined immunodeficiency mice alleviated the antibody-induced hypothermia, lung damage, and mortality, suggesting that T lymphocytes were responsible for the protective effect. Taken together, these results suggest that recipient T lymphocytes play a significant role in suppressing antibody-mediated TRALI reactions. They identify a potentially new recipient mechanism that controls the severity of TRALI reactions.


2009 ◽  
Vol 296 (6) ◽  
pp. L1002-L1011 ◽  
Author(s):  
James H. Finigan ◽  
Adel Boueiz ◽  
Emily Wilkinson ◽  
Rachel Damico ◽  
Jarrett Skirball ◽  
...  

The coagulation system is central to the pathophysiology of acute lung injury. We have previously demonstrated that the anticoagulant activated protein C (APC) prevents increased endothelial permeability in response to edemagenic agonists in endothelial cells and that this protection is dependent on the endothelial protein C receptor (EPCR). We currently investigate the effect of APC in a mouse model of ventilator-induced lung injury (VILI). C57BL/6J mice received spontaneous ventilation (control) or mechanical ventilation (MV) with high (HVT; 20 ml/kg) or low (LVT; 7 ml/kg) tidal volumes for 2 h and were pretreated with APC or vehicle via jugular vein 1 h before MV. In separate experiments, mice were ventilated for 4 h and received APC 30 and 150 min after starting MV. Indices of capillary leakage included bronchoalveolar lavage (BAL) total protein and Evans blue dye (EBD) assay. Changes in pulmonary EPCR protein and Rho-associated kinase (ROCK) were assessed using SDS-PAGE. Thrombin generation was measured via plasma thrombin-antithrombin complexes. HVT induced pulmonary capillary leakage, as evidenced by significant increases in BAL protein and EBD extravasation, without significantly increasing thrombin production. HVT also caused significant decreases in pulmonary, membrane-bound EPCR protein levels and increases in pulmonary ROCK-1. APC treatment significantly decreased pulmonary leakage induced by MV when given either before or after initiation of MV. Protection from capillary leakage was associated with restoration of EPCR protein expression and attenuation of ROCK-1 expression. In addition, mice overexpressing EPCR on the pulmonary endothelium were protected from HVT-mediated injury. Finally, gene microarray analysis demonstrated that APC significantly altered the expression of genes relevant to vascular permeability at the ontology (e.g., blood vessel development) and specific gene (e.g., MAPK-associated kinase 2 and integrin-β6) levels. These findings indicate that APC is barrier-protective in VILI and that EPCR is a critical participant in APC-mediated protection.


2005 ◽  
Vol 289 (4) ◽  
pp. L583-L590 ◽  
Author(s):  
Xinchun Lin ◽  
Huan Yang ◽  
Tohru Sakuragi ◽  
Maowen Hu ◽  
Lin L. Mantell ◽  
...  

High mobility group box 1 (HMGB1) protein, a late mediator of lethality in sepsis, can induce acute inflammatory lung injury. Here, we identify the critical role of α-chemokine receptors in the HMGB1-induced inflammatory injury and show that α-chemokine receptor inhibition increases survival in sepsis, in a clinically relevant time frame. Intratracheal instillation of recombinant HMGB1 induces a neutrophilic leukocytosis, preceded by alveolar accumulation of the α-chemokine macrophage inflammatory protein-2 and accompanied by injury and increased inflammatory potential within the air spaces. To investigate the role of α-chemokine receptors in the injury, we instilled recombinant HMGB1 (0.5 μg) directly into the lungs and administered a subcutaneous α-chemokine receptor inhibitor, Antileukinate (200 μg). α-Chemokine receptor blockade reduced HMGB1-induced inflammatory injury (neutrophils: 2.9 ± 3.2 vs. 8.1 ± 2.4 × 104cells; total protein: 120 ± 48 vs. 311 ± 129 μg/ml; reactive nitrogen species: 2.3 ± 0.3 vs. 3.5 ± 1.3 μM; and macrophage migration inhibitory factor: 6.4 ± 4.2 vs. 37.4 ± 15.9 ng/ml) within the bronchoalveolar lavage fluid, indicating that HMGB1-induced inflammation and injury are α-chemokine mediated. Because HMGB1 can mediate late septic lethality, we administered Antileukinate to septic mice and observed increased survival (from 58% in controls to 89%) even when the inhibitor treatment was initiated 24 h after the induction of sepsis. These data demonstrate that α-chemokine receptor inhibition can reduce HMGB1-induced lung injury and lethality in established sepsis and may provide a novel treatment in this devastating disease.


Shock ◽  
2019 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Antony Leonard ◽  
Pei Yi Su ◽  
David I. Yule ◽  
Arshad Rahman ◽  
Fabeha Fazal

Author(s):  
Kenji Tsushima ◽  
Franco R. D'Alessio ◽  
Neil R. Aggarwal ◽  
D.Clark Files ◽  
Venkataramana Sidhaye ◽  
...  

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