scholarly journals Opposite effects of ANP receptors in attenuation of LPS-induced endothelial permeability and lung injury

2012 ◽  
Vol 83 (2) ◽  
pp. 194-199 ◽  
Author(s):  
Junjie Xing ◽  
Bakhtiyor Yakubov ◽  
Valeriy Poroyko ◽  
Anna A. Birukova
Keyword(s):  
Lung Injury ◽  
Endothelial Permeability ◽  
Anp Receptors

Abstract 73: Bone Morphogenetic Protein Activity Modulates Endothelial Barrier Function

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Thomas Helbing ◽  
Elena Ketterer ◽  
Bianca Engert ◽  
Jennifer Heinke ◽  
Sebastian Grundmann ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Barrier Function ◽  
Endothelial Permeability ◽  
Bmp Signaling ◽  
Endothelial Barrier ◽  
Endothelial Barrier Function

Introduction: Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome, are associated with high morbidity and mortality in patients. During the progression of ALI, the endothelial cell barrier of the pulmonary vasculature becomes compromised, leading to pulmonary edema, a characteristic feature of ALI. It is well-established that EC barrier dysfunction is initiated by cytoskeletal remodeling, which leads to disruption of cell-cell contacts and formation of paracellular gaps, allowing penetration of protein-rich fluid and inflammatory cells. Bone morphogenetic proteins (BMPs) are important players in endothelial dysfunction and inflammation but their effects on endothelial permeability in ALI have not been investigated until now. Methods and Results: As a first approach to assess the role of BMPs in acute lung injury we analysed BMP4 and BMPER expression in an infectious (LPS) and a non-infectious (bleomycin) mouse models of acute lung injury. In both models BMP4 and BMPER protein expression levels were reduced demonstrated by western blots, suggesting that BMPs are involved in progression ALI. To assess the role of BMPs on vascular leakage, a key feature of ALI, BMP activity in mice was inhibited by i.p. administration of LDN193189, a small molecule that blocks BMP signalling. After 3 days Evans blue dye (EVB) was administered i.v. and dye extravasation into the lungs was quantified as a marker for vascular leakage. Interestingly, LDN193189 significantly increased endothelial permeability compared to control lungs, indicating that BMP signaling is involved in maintenance of endothelial barrier function. To quantify effects of BMP inhibition on endothelial barrier function in vitro, HUVECs were seeded onto transwell filters and were exposed to LDN193189. After 3 days FITC-dextrane was added and passage into the lower chamber was quantified as a marker for endothelial barrier function. Thrombin served as a positive control. As expected from our in vivo experiments inhibition of BMP signaling by LDN193189 enhanced FITC-dextrane passage. To study specific effects of BMPs on endothelial barrier function, two protagonist of the BMP family, BMP2 and BMP4, or BMP modulator BMPER were tested in the transwell assay in vitro. Interestingly BMP4 and BMPER, but not BMP2, reduced FITC-dextrane passage demonstrating that BMP4 and BMPER improved endothelial barrier function. Vice versa, specific knock down of BMP4 or BMPER increased leakage in transwell assays. Im immuncytochemistry silencing of BMPER or BMP4 induced hyperpermeability as a consequence of a pro-inflammatory endothelial phenotype characterised by reduced cell-cell contacts and increased actin stress fiber formation. Additionally, the pro-inflammatory endothelial phenotype was confirmed by real-time revealing increased expression of adhesion molecules ICAM-1 or proinflammatory cytokines such as IL-6 and IL-8 in endothelial cells after BMPER or BMP4 knock down. Confirming these in vitro results BMPER +/- mice exhibit increased extravasation of EVB into the lungs, indicating that partial loss of BMPER impairs endothelial barrier function in vitro and in vivo. Conclusion: We identify BMPER and BMP4 as local regulators of vascular permeability. Both are protective for endothelial barrier function and may open new therapeutic avenues in the treatment of acute lung injury.

scholarly journals Metformin-stimulated AMPK-α1 promotes microvascular repair in acute lung injury

2013 ◽  
Vol 305 (11) ◽  
pp. L844-L855 ◽  
Author(s):  
Ming-Yuan Jian ◽  
Mikhail F. Alexeyev ◽  
Paul E. Wolkowicz ◽  
Jaroslaw W. Zmijewski ◽  
Judy R. Creighton
Keyword(s):  
Endothelial Cells ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Ex Vivo ◽  
Endothelial Permeability ◽  
Beneficial Effects ◽  
Isolated Lung

Acute lung injury secondary to sepsis is a leading cause of mortality in sepsis-related death. Present therapies are not effective in reversing endothelial cell dysfunction, which plays a key role in increased vascular permeability and compromised lung function. AMP-activated protein kinase (AMPK) is a molecular sensor important for detection and mediation of cellular adaptations to vascular disruptive stimuli. In this study, we sought to determine the role of AMPK in resolving increased endothelial permeability in the sepsis-injured lung. AMPK function was determined in vivo using a rat model of endotoxin-induced lung injury, ex vivo using the isolated lung, and in vitro using cultured rat pulmonary microvascular endothelial cells (PMVECs). AMPK stimulation using N1-(α-d-ribofuranosyl)-5-aminoimidizole-4-carboxamide or metformin decreased the LPS-induced increase in permeability, as determined by filtration coefficient ( Kf) measurements, and resolved edema as indicated by decreased wet-to-dry ratios. The role of AMPK in the endothelial response to LPS was determined by shRNA designed to decrease expression of the AMPK-α1 isoform in capillary endothelial cells. Permeability, wounding, and barrier resistance assays using PMVECs identified AMPK-α1 as the molecule responsible for the beneficial effects of AMPK in the lung. Our findings provide novel evidence for AMPK-α1 as a vascular repair mechanism important in the pulmonary response to sepsis and identify a role for metformin treatment in the management of capillary injury.

scholarly journals Substrate stiffness-dependent exacerbation of endothelial permeability and inflammation: mechanisms and potential implications in ALI and PH (2017 Grover Conference Series)

2018 ◽  
Vol 8 (2) ◽  
pp. 204589401877304 ◽  
Author(s):  
Pratap Karki ◽  
Anna A. Birukova
Keyword(s):  
Lung Injury ◽  
Inflammatory Responses ◽  
Mechanical Strain ◽  
Endothelial Permeability ◽  
Endothelial Barrier ◽  
In Vivo Studies ◽  
Potential Implication ◽  
Vascular Stiffening ◽  
Life Threatening

The maintenance of endothelial barrier integrity is absolutely essential to prevent the vascular leak associated with pneumonia, pulmonary edema resulting from inhalation of toxins, acute elevation to high altitude, traumatic and septic lung injury, acute lung injury (ALI), and its life-threatening complication, acute respiratory distress syndrome (ARDS). In addition to the long-known edemagenic and inflammatory agonists, emerging evidences suggest that factors of endothelial cell (EC) mechanical microenvironment such as blood flow, mechanical strain of the vessel, or extracellular matrix stiffness also play an essential role in the control of endothelial permeability and inflammation. Recent studies from our group and others have demonstrated that substrate stiffening causes endothelial barrier disruption and renders EC more susceptible to agonist-induced cytoskeletal rearrangement and inflammation. Further in vivo studies have provided direct evidence that proinflammatory stimuli increase lung microvascular stiffness which in turn exacerbates endothelial permeability and inflammation and perpetuates a vicious circle of lung inflammation. Accumulating evidence suggests a key role for RhoA GTPases signaling in stiffness-dependent mechanotransduction mechanisms defining EC permeability and inflammatory responses. Vascular stiffening is also known to be a key contributor to other cardiovascular diseases such as arterial pulmonary hypertension (PH), although the precise role of stiffness in the development and progression of PH remains to be elucidated. This review summarizes the current understanding of stiffness-dependent regulation of pulmonary EC permeability and inflammation, and discusses potential implication of pulmonary vascular stiffness alterations at macro- and microscale in development and modulation of ALI and PH.

Abstract 13667: Programming to S1PR1 + Endothelial Cell Population Promotes the Restoration of Vascular Integrity in vivo

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Zahid Akhter ◽  
Jagdish Chandra Joshi ◽  
Vijay Avin Balaji Ragunathrao ◽  
Richard L Proia ◽  
Asrar B Malik ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Lung Injury ◽  
Endothelial Permeability ◽  
Vascular Diseases ◽  
Mechanistic Study ◽  
Rna Seq ◽  
Vascular Integrity ◽  
Injured Lung ◽  
Sphingosine 1 Phosphate

Introduction: Increased endothelial permeability and failure to repair is the hallmark of several vascular diseases including acute lung injury (ALI). However, little is known about the intrinsic pathways that activate the endothelial cell (EC) regenerative programs facilitating thereby tissue repair. Studies have invoked a crucial role of sphingosine-1-phosphate (S1P) in resolving endothelial hyperpermeability through activation of the G-protein coupled receptor, sphingosine-1-phosphate receptor 1 (S1PR1). Hypothesis: We postulate that S1PR1 + EC serve as an endogenous means to prevent endothelial injury. Methods: Studies were made using EC-S1PR1 null mice and S1PR1-GFP reporter mice to trace the generation and characteristics of S1PR1 + EC by exploiting immuno-histochemical analysis and FACS. RNA-seq analysis was performed to identify the genetic signature of S1PR1 + EC. Combination of genetic and pharmacological strategies were included for mechanistic study. Transplantation of S1PR1 + EC and edema measurement was performed in EC-S1PR1 null mice. Results: We observed in a mouse model of endotoxemia that LPS via generation of S1P induced the programming of S1PR1 lo EC to S1PR1 + EC, comprising 80% of lung EC. Their generation preceded the vascular repair phase and these cells were required for reestablishing the endothelial barrier function. Thus, conditional deletion of S1PR1 in EC spontaneously increased lung vascular permeability. RNA-seq analysis of S1PR1 + EC showed enrichment of genes regulating S1P synthesis and transport, sphingosine kinase 1 (SPHK1) and SPNS2, respectively, as well as transcription factors EGR1 and STAT3. EGR1 and STAT3 were essential for transcribing SPHK1 and SPNS2, respectively to increase S1P concentration that served to amplify S1PR1 + EC transition. Transplantation of S1PR1 + EC into injured lung vasculature of EC-S1PR1 -/- mice restored endothelial integrity. Conclusions: Findings illustrate that generation of a specialized S1PR1 + EC population has the potential to activate key endothelial regenerative program mediating vascular endothelial repair raising the possibility of activating this pathway to restore vascular homeostasis in inflammatory lung injury.

Endothelial NOS Uncoupling Contributes To Endothelial Permeability In Inflammatory Acute Lung Injury

2012 ◽  
Author(s):  
William S. Szczepaniak ◽  
Eric E. Kelley ◽  
Sruti Shiva ◽  
Mark T. Gladwin ◽  
Bryan J. McVerry
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Endothelial Permeability

scholarly journals Asef controls vascular endothelial permeability and barrier recovery in the lung

2015 ◽  
Vol 26 (4) ◽  
pp. 636-650 ◽  
Author(s):  
Xinyong Tian ◽  
Yufeng Tian ◽  
Grzegorz Gawlak ◽  
Fanyong Meng ◽  
Yoshihiro Kawasaki ◽  
...  
Keyword(s):  
Lung Injury ◽  
Endothelial Permeability ◽  
Dominant Negative ◽  
Nucleotide Exchange ◽  
Protective Mechanisms ◽  
Compensatory Response ◽  
Cytoskeletal Dynamics ◽  
Rac1 Gtpase ◽  
Gtpase Activation

Increased levels of hepatocyte growth factor (HGF) in injured lungs may reflect a compensatory response to diminish acute lung injury (ALI). HGF-induced activation of Rac1 GTPase stimulates endothelial barrier protective mechanisms. This study tested the involvement of Rac-specific guanine nucleotide exchange factor Asef in HGF-induced endothelial cell (EC) cytoskeletal dynamics and barrier protection in vitro and in a two-hit model of ALI. HGF induced membrane translocation of Asef and stimulated Asef Rac1-specific nucleotide exchange activity. Expression of constitutively activated Asef mutant mimicked HGF-induced peripheral actin cytoskeleton enhancement. In contrast, siRNA-induced Asef knockdown or expression of dominant-negative Asef attenuated HGF-induced Rac1 activation evaluated by Rac-GTP pull down and FRET assay with Rac1 biosensor. Molecular inhibition of Asef attenuated HGF-induced peripheral accumulation of cortactin, formation of lamellipodia-like structures, and enhancement of VE-cadherin adherens junctions and compromised HGF-protective effect against thrombin-induced RhoA GTPase activation, Rho-dependent cytoskeleton remodeling, and EC permeability. Intravenous HGF injection attenuated lung inflammation and vascular leak in the two-hit model of ALI induced by excessive mechanical ventilation and thrombin signaling peptide TRAP6. This effect was lost in Asef− /− mice. This study shows for the first time the role of Asef in HGF-mediated protection against endothelial hyperpermeability and lung injury.

scholarly journals The Protection Effect of Ulinastatin on Freshwater Instillation-Induced Acute Lung Injury in Rabbits

2021 ◽  
Author(s):  
Shaosong Xi ◽  
Le Huan ◽  
Hongyan Wu ◽  
Ying Zhu ◽  
Wei Hu ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Inflammatory Cytokines ◽  
Large Dose ◽  
Weight Ratio ◽  
Endothelial Permeability ◽  
Potential Candidate ◽  
Protective Effects ◽  
Arterial Blood ◽  
Vegf Pathway

Abstract Background: Drowning is an important cause of accidental death in humans. The main cause of death following drowning is pulmonary oedema or lung injury, eventually leading to acute respiratory distress syndrome. The present study aimed to determine the protective effects of Ulinastatin on freshwater-induced acute drowning lung injury. Methods: Rabbits were randomly divided into a control, freshwater, freshwater + small-dose Ulinastatin, freshwater + medium-dose Ulinastatin, freshwater + large-dose Ulinastatin group. The arterial blood gas analysis was performed before modelling (baseline) and at various time points after freshwater instillation. And then, the wet-to-dry weight ratio lung permeability index were measured to detect the effect of Ulinastatin on lung endothelial permeability. Furthermore, histopathological staining and ELISAs were used to analyse the histological changes and inflammatory cytokines expression resulted from lung injury, respectively. Western blotting and Quantitative real-time polymerase chain reaction were used to measure the protein and mRNA levels of Hypoxia inducible factor-lα (HIF-1α)/ Vascular endothelial growth factor (VEGF) in the lung tissues. Results: By inhibiting the HIF-1α/VEGF pathway, treatment with Ulinastatin at a large dose could markedly attenuate changes in the PaO2/FiO2 (P/F), lung endothelial permeability, histopathology, and the expression of inflammatory cytokines induced by freshwater instillation. Conclusion: Ulinastatin is a potential candidate treatment for freshwater drowning-induced acute lung injury that targets the HIF-1α/VEGF pathway.

Isoacteoside Attenuates Septic Acute Lung Injury by Inhibiting Inflammation, Oxidative Stress and Endothelial Hyperpermeability in Mice

2021 ◽  
Author(s):  
Yan-nian Luo ◽  
Nan-nan He ◽  
Juan Xu ◽  
Rui Wang ◽  
Wen Cao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Acute Lung Injury ◽  
Survival Rate ◽  
Lung Injury ◽  
Cecal Ligation ◽  
Endothelial Permeability ◽  
Mouse Serum ◽  
Control Group ◽  
Expression Levels ◽  
Endothelial Hyperpermeability

Abstract The present study was aimed to explore the protective role of isoacteoside (ISO) in cecal ligation and puncture (CLP)-induced acute lung injury (ALI) in mice. Mice were divided into the following groups: sham control group, ALI group, and ALI+ISO group, in which mice received 10,50 or 100 mg/kg/day of ISO for 3 days before, 0h and 12h after CLP surgery. In the first experiment, all mice were maintained until 72 h after the CLP operation to calculate the survival rate. In the second experiment, mouse serum and lung and bronchoalveolar lavage fluid (BALF) were collected 24 h after model establishment for detection. The results revealed that ISO significantly improved the ALI associated survival rate, reduced the pathological injury, ALI score, infiltration of inflammatory cells, leakage of cells and proteins into BALF, systemic and local cytokine secretion, and pulmonary oxidative stress. Moreover, ISO significantly inhibited the expression levels of the pro-inflammatory proteins TLR4, MyD88, p-NF-κB p65, p-IKKαβ, and p-IκBα and increased the expression levels of the endothelial permeability related proteins ZO-1, claudin 5 and VE-cadherin. In conclusions, ISO mitigated acute lung injury in mice which was attributed to the capacity of ISO to inhibit inflammation, oxidative stress and endothelial hyperpermeability.

scholarly journals MicroRNA dysregulation in lung injury: the role of the miR-26a/EphA2 axis in regulation of endothelial permeability

2018 ◽  
Vol 315 (4) ◽  
pp. L584-L594 ◽  
Author(s):  
Ryan J. Good ◽  
Laura Hernandez-Lagunas ◽  
Ayed Allawzi ◽  
Joanne K. Maltzahn ◽  
Christine U. Vohwinkel ◽  
...  
Keyword(s):  
Lung Injury ◽  
Endothelial Permeability ◽  
Regulate Gene Expression ◽  
Pulmonary Endothelium ◽  
Mirna Array ◽  
Regulated Expression ◽  
Injured Lung ◽  
Microrna Dysregulation

MicroRNAs (miRNAs) are noncoding RNAs that regulate gene expression in many diseases, although the contribution of miRNAs to the pathophysiology of lung injury remains obscure. We hypothesized that dysregulation of miRNA expression drives the changes in key genes implicated in the development of lung injury. To test our hypothesis, we utilized a model of lung injury induced early after administration of intratracheal bleomycin (0.1 U). Wild-type mice were treated with bleomycin or PBS, and lungs were collected at 4 or 7 days. A profile of lung miRNA was determined by miRNA array and confirmed by quantitative PCR and flow cytometry. Lung miR-26a was significantly decreased 7 days after bleomycin injury, and, on the basis of enrichment of predicted gene targets, it was identified as a putative regulator of cell adhesion, including the gene targets EphA2, KDR, and ROCK1, important in altered barrier function. Lung EphA2 mRNA, and protein increased in the bleomycin-injured lung. We further explored the miR-26a/EphA2 axis in vitro using human lung microvascular endothelial cells (HMVEC-L). Cells were transfected with miR-26a mimic and inhibitor, and expression of gene targets and permeability was measured. miR-26a regulated expression of EphA2 but not KDR or ROCK1. Additionally, miR-26a inhibition increased HMVEC-L permeability, and the disrupted barrier integrity due to miR-26a was blocked by EphA2 knockdown, shown by VE-cadherin staining. Our data suggest that miR-26a is an important epigenetic regulator of EphA2 expression in the pulmonary endothelium. As such, miR-26a may represent a novel therapeutic target in lung injury by mitigating EphA2-mediated changes in permeability.

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