scholarly journals Electrical method for detection of endothelial cell shape change in real time: assessment of endothelial barrier function.

1992 ◽  
Vol 89 (17) ◽  
pp. 7919-7923 ◽  
Author(s):  
C. Tiruppathi ◽  
A. B. Malik ◽  
P. J. Del Vecchio ◽  
C. R. Keese ◽  
I. Giaever
2021 ◽  
Vol 19 ◽  
pp. 205873922110623
Author(s):  
Hisatake Mori ◽  
Muhammad Aminul Huq ◽  
Md. Monirul Islam ◽  
Naoshi Takeyama

Introduction: Acute respiratory response syndrome (ARDS) leads to increased permeability of the endothelial-epithelial barrier, which in turn promotes edema formation and hypoxemic respiratory failure. Although activated neutrophils are thought to play a significant role in mediating ARDS, at present the contribution of neutrophil extracellular traps (NETs) to lung endothelial barrier function is unclear. Methods: To clarify their role, we co-cultured in vitro NETs induced by phorbol myristate acetate (PMA)–activated neutrophils with lung endothelial cell monolayers and examined the barrier function of lung endothelial cells by immunofluorescence microscopy and albumin permeability in a double-chamber culture method. Results: Co-culture with stimulated neutrophils increased the albumin permeability of the human pulmonary artery endothelial cell (HPAEC) monolayer and altered cytoskeleton F-actin and vascular endothelial-cadherin in cell-cell junctions. Hyperpermeability to albumin and histological alterations were prevented by inhibition of NET formation with peptidyl arginine deiminase inhibitor or a neutrophil elastase inhibitor and were also prevented by increased degradation of NET structure with DNase. Conclusion: This in vitro experiment shows that altered HPAEC barrier function and increased albumin permeability are caused by the direct effect of PMA-induced NETs and their components. NET formation may be involved in the increased vascular permeability of the lung, which is a common feature in ARDS of various etiologies. These insights may help generate novel approaches for medical interventions.


2006 ◽  
Vol 282 (11) ◽  
pp. 7833-7843 ◽  
Author(s):  
Itender Singh ◽  
Nebojsa Knezevic ◽  
Gias U. Ahmmed ◽  
Vidisha Kini ◽  
Asrar B. Malik ◽  
...  

2005 ◽  
Vol 79 (16) ◽  
pp. 10442-10450 ◽  
Author(s):  
Victoria M. Wahl-Jensen ◽  
Tatiana A. Afanasieva ◽  
Jochen Seebach ◽  
Ute Ströher ◽  
Heinz Feldmann ◽  
...  

ABSTRACT Ebola virus causes severe hemorrhagic fever with high mortality rates in humans and nonhuman primates. Vascular instability and dysregulation are disease-decisive symptoms during severe infection. While the transmembrane glycoprotein GP1,2 has been shown to cause endothelial cell destruction, the role of the soluble glycoproteins in pathogenesis is largely unknown; however, they are hypothesized to be of biological relevance in terms of target cell activation and/or increase of endothelial permeability. Here we show that virus-like particles (VLPs) consisting of the Ebola virus matrix protein VP40 and GP1,2 were able to activate endothelial cells and induce a decrease in barrier function as determined by impedance spectroscopy and hydraulic conductivity measurements. In contrast, the soluble glycoproteins sGP and Δ-peptide did not activate endothelial cells or change the endothelial barrier function. The VLP-induced decrease in barrier function was further enhanced by the cytokine tumor necrosis factor alpha (TNF-α), which is known to induce a long-lasting decrease in endothelial cell barrier function and is hypothesized to play a key role in Ebola virus pathogenesis. Surprisingly, sGP, but not Δ-peptide, induced a recovery of endothelial barrier function following treatment with TNF-α. Our results demonstrate that Ebola virus GP1,2 in its particle-associated form mediates endothelial cell activation and a decrease in endothelial cell barrier function. Furthermore, sGP, the major soluble glycoprotein of Ebola virus, seems to possess an anti-inflammatory role by protecting the endothelial cell barrier function.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
H Giral Arnal ◽  
A Kratzer ◽  
M Moobed ◽  
U Landmesser

Abstract Introduction Inflammation is essential for the protective response of the immune system. However, hyperactivated inflammation and dysregulated resolution strongly associates with the pathophysiology of atherosclerosis and ischemia-induced injury after myocardial infarction. Therefore, attenuation of inflammatory response has emerged as a promising approach to reduce cardiovascular disease burden. A limiting step of inflammation is the local recruitment of leukocytes to the lesion, a process regulated by intense cross-talk between immune and endothelial cells. A better understanding of the modulatory mechanisms of adhesion is paramount for the development of better therapies. Purpose Identify endothelial miRNAs that impact leukocyte adhesion and characterize the underlying pathways that regulate this process. Methods A functional high-throughput screening (HTS) of human miRNA libraries (mimics and inhibitors) measured miRNA impact on monocyte (THP-1) adhesion to an endothelial monolayer (HAEC). Individually miRNAs were transfected in HAEC and fluorescently-labeled monocyte attachment was recorded by a robotic automated microscopy platform. Computational analysis lead to identification of potential targets and relevant pathways associated to the action of candidate miRNAs. Further validation of promising targets was performed by qPCR and western blotting. Additional endothelial phenotypic properties such as cytoskeleton morphology or endothelial barrier function were analyzed in the presence of specific miRNAs. Results Functional HTS and secondary screening resulted in 38 microRNAs that reduced and 2 that increased monocyte adhesion. Bioinformatic target prediction and pathway analysis narrowed the set of miRNA candidates used for characterization studies. These miRNAs significantly modulated cell adhesion of both monocytic-leukemia THP-1 cells and freshly isolated human CD14+ monocytes, but effect on CD14+ was weaker compared to THP-1. Several miRNAs induced severe changes on endothelial cell morphology, likely due to cytoskeleton rearrangement. We identified and validated several miRNA targets belonging to the Ras GTPase family of actin remodeling modulators (RalA, RAP1A). Additionally, a few miRNAs targeted Ephrin signaling molecules (EFNs, EPHs) which mediate multiple cell functions including cell-cell contacts. We also explored miRNA effects on endothelial barrier function and measured monocyte adhesion under physiological and disturbed flow conditions. Conclusions We identified a set of miRNAs able to modulate monocyte cell adhesion to endothelial cells under inflammatory conditions. Potential mechanistic pathways of miRNA modulation of adhesion included Ephrin signaling pathway and Ras GTPase family. A better understanding of the role of specific microRNAs regulating the immune-endothelial cell interaction may lead to novel therapeutic strategies in atherosclerosis and myocardial infarction. Acknowledgement/Funding DZHK (German Centre for Cardiovascular Research), partner site Berlin, Germany; Berlin Institute of Health (BIH)


Blood ◽  
2005 ◽  
Vol 105 (5) ◽  
pp. 1950-1955 ◽  
Author(s):  
Xavier Cullere ◽  
Sunil K. Shaw ◽  
Lorna Andersson ◽  
Junichi Hirahashi ◽  
Francis W. Luscinskas ◽  
...  

Abstract Endothelial cell-cell junctional proteins and cortical actin are of central importance for regulating vascular permeability. Rap1, a member of the Ras family of GTPases, is enriched at endothelial cell-cell contacts and activated by cyclic AMP (cAMP) through a PKA-independent pathway. Activation of a cAMP-inducible guanine-exchange factor for Rap, Epac, results in markedly enhanced basal endothelial barrier function by increasing cortical actin and subsequent redistribution of adherens and tight junctional molecules to cell-cell contacts. Activation of Epac also counteracts thrombin-induced hyperpermeability through down-regulation of Rho GTPase activation, suggesting cross-talk between Rap and Rho GT-Pases. Thus, Epac/Rap activation represents a new pathway for regulating endothelial cell barrier function.


2014 ◽  
Vol 112 (12) ◽  
pp. 1088-1102 ◽  
Author(s):  
Beatriz Marcos-Ramiro ◽  
Diego García-Weber ◽  
Jaime Millán

SummaryThe decrease of endothelial barrier function is central to the long-term inflammatory response. A pathological alteration of the ability of endothelial cells to modulate the passage of cells and solutes across the vessel underlies the development of inflammatory diseases such as atherosclerosis and multiple sclerosis. The inflammatory cytokine tumour necrosis factor (TNF) mediates changes in the barrier properties of the endothelium. TNF activates different Rho GTPases, increases filamentous actin and remodels endothelial cell morphology. However, inhibition of actin-mediated remodelling is insufficient to prevent endothelial barrier disruption in response to TNF, suggesting that additional molecular mechanisms are involved. Here we discuss, first, the pivotal role of Rac-mediated generation of reactive oxygen species (ROS) to regulate the integrity of endothelial cell-cell junctions and, second, the ability of endothelial adhesion receptors such as ICAM-1, VCAM-1 and PECAM-1, involved in leukocyte transendothelial migration, to control endothelial permeability to small molecules, often through ROS generation. These adhesion receptors regulate endothelial barrier function in ways both dependent on and independent of their engagement by immune cells, and orchestrate the crosstalk between leukocyte transendothelial migration and endothelial permeability during inflammation.


1993 ◽  
Vol 264 (4) ◽  
pp. C894-C905 ◽  
Author(s):  
S. E. Goldblum ◽  
X. Ding ◽  
J. Campbell-Washington

Tumor necrosis factor-alpha (TNF-alpha) influences pulmonary vascular endothelial barrier function in vitro. We studied whether recombinant TNF-alpha (rTNF-alpha) regulates endothelial barrier function through actin reorganization. Postconfluent bovine pulmonary artery endothelial cell monolayers were exposed to human rTNF-alpha (1,000 U/ml) and evaluated for 1) transendothelial [14C]albumin flux, 2) F-actin organization with fluorescence microscopy, 3) F-actin quantitation by spectrofluorometry, and 4) monomeric G-actin levels by the deoxyribonuclease I inhibition assay. rTNF-alpha induced increments in [14C]albumin flux (P < 0.04) and intercellular gap formation at > or = 2-6 h. During this same time, the endothelial F-actin pool decreased (P = 0.0064), with reciprocal increases in the G-actin pool (P < 0.0001). Prior F-actin stabilization with phallicidin protected against the rTNF-alpha-induced increments in G-actin (P < 0.002) as well as changes in barrier function (P < 0.01). Prior protein synthesis inhibition enhanced the rTNF-alpha-induced decrement in F-actin (P < 0.0001), blunted the G-actin increment (P < 0.002), and increased rTNF-alpha-induced changes in endothelial barrier function (P < 0.003). Therefore, rTNF-alpha induces pulmonary vascular endothelial F-actin depolymerization, intercellular gap formation, and barrier dysfunction. rTNF-alpha also increased total actin (P < 0.02) and new actin synthesis (P < 0.002), which may be a compensatory endothelial cell response to rTNF-alpha-induced F-actin depolymerization.


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