Role of Rho GTPases in the regulation of pulmonary endothelial barrier function and angiogenesis

2012 ◽  
Vol 56 (5-6) ◽  
pp. 326-327
Author(s):  
Beata Wojciak-Stothard
Keyword(s):  
Barrier Function ◽  
Rho Gtpases ◽  
Endothelial Barrier ◽  
Endothelial Barrier Function

Hypothermia induced loss of endothelial barrier function is restored after dopamine pre-treatment; role of ERK activation

2006 ◽  
Vol 45 (3) ◽  
pp. e80
Author(s):  
Boris Rudic ◽  
Paul Thomas Brinkkoetter ◽  
Grietje Beck ◽  
Uwe Gottmann ◽  
Claude Braun ◽  
...  
Keyword(s):  
Barrier Function ◽  
Endothelial Barrier ◽  
Endothelial Barrier Function ◽  
Erk Activation ◽  
Pre Treatment

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 FBXW7 regulates endothelial barrier function by suppression of the cholesterol synthesis pathway and prenylation of RhoB

2019 ◽  
Vol 30 (5) ◽  
pp. 607-621 ◽  
Author(s):  
Manon C. A. Pronk ◽  
Jisca Majolée ◽  
Anke Loregger ◽  
Jan S. M. van Bezu ◽  
Noam Zelcer ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Barrier Function ◽  
Rho Gtpases ◽  
Umbilical Vein ◽  
Cholesterol Biosynthesis ◽  
Endothelial Barrier ◽  
Biosynthesis Pathway ◽  
Endothelial Barrier Function ◽  
Cholesterol Biosynthesis Pathway

Rho GTPases control both the actin cytoskeleton and adherens junction stability and are recognized as essential regulators of endothelial barrier function. They act as molecular switches and are primarily regulated by the exchange of GDP and GTP. However, posttranslational modifications such as phosphorylation, prenylation, and ubiquitination can additionally alter their localization, stability, and activity. F-box proteins are involved in the recognition of substrate proteins predestined for ubiquitination and subsequent degradation. Given the importance of ubiquitination, we studied the effect of the loss of 62 members of the F-box protein family on endothelial barrier function in human umbilical vein endothelial cells. Endothelial barrier function was quantified by electrical cell impedance sensing and macromolecule passage assay. Our RNA interference–based screen identified FBXW7 as a key regulator of endothelial barrier function. Mechanistically, loss of FBXW7 induced the accumulation of the RhoB GTPase in endothelial cells, resulting in their increased contractility and permeability. FBXW7 knockdown induced activation of the cholesterol biosynthesis pathway and changed the prenylation of RhoB. This effect was reversed by farnesyl transferase inhibitors and by the addition of geranylgeranyl pyrophosphate. In summary, this study identifies FBXW7 as a novel regulator of endothelial barrier function in vitro. Loss of FBXW7 indirectly modulates RhoB activity via alteration of the cholesterol biosynthesis pathway and, consequently, of the prenylation status and activity of RhoB, resulting in increased contractility and disruption of the endothelial barrier.

Role of Protein Kinase C Isoforms in Rat Epididymal Microvascular Endothelial Barrier Function

2003 ◽  
Vol 28 (5) ◽  
pp. 626-636 ◽  
Author(s):  
Elizabeth O. Harrington ◽  
Jodi L. Brunelle ◽  
Christopher J. Shannon ◽  
Eric S. Kim ◽  
Kirstin Mennella ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Barrier Function ◽  
Endothelial Barrier ◽  
Endothelial Barrier Function ◽  
Kinase C ◽  
Microvascular Endothelial ◽  
Protein Kinase C Isoforms

scholarly journals Driving Rho GTPase activity in endothelial cells regulates barrier integrity

2010 ◽  
Vol 103 (01) ◽  
pp. 40-55 ◽  
Author(s):  
Cora Beckers ◽  
Victor van Hinsbergh ◽  
Geerten van Nieuw Amerongen
Keyword(s):  
Barrier Function ◽  
Rho Gtpases ◽  
Rho Gtpase ◽  
Three Dimensional ◽  
Regulatory Proteins ◽  
Endothelial Barrier ◽  
Endothelial Barrier Function ◽  
Barrier Dysfunction ◽  
Gtpase Activation ◽  
The Individual

SummaryIn the past decade understanding of the role of the Rho GTPases RhoA, Rac1 and Cdc42 has been developed from regulatory proteins that regulate specific actin cytoskeletal structures – stress fibers, lamellipodia and filopodia – to complex integrators of cytoskeletal structures that can exert multiple functions depending on the cellular context. Fundamental to these functions are three-dimensional complexes between the individual Rho GTPases, their specific activators (GEFs) and inhibitors (GDIs and GAPs), which greatly outnumber the Rho GTPases themselves, and additional regulatory proteins. By this complexity of regulation different vasoactive mediators can induce various cytoskeletal structures that enable the endothelial cell (EC) to respond adequately. In this review we have focused on this complexity and the consequences of Rho GTPase regulation for endothelial barrier function. The permeability inducers thrombin and VEGF are presented as examples of G-protein coupled receptor- and tyrosine kinase receptormediated Rho GTPase activation, respectively. These mediators induce complex but markedly different networks of activators, inhibitors and effectors of Rho GTPases, which alter the endothelial barrier function. An interesting feature in this regulation is that Rho GTPases often have both barrier-protecting and barrier-disturbing functions. While Rac1 enforces the endothelial junctions, it becomes part of a barrier-disturbing mechanism as activator of reactive oxygen species generating NADPH oxidase. Similarly RhoA is protective under basal conditions, but becomes involved in barrier dysfunction after activation of ECs by thrombin. The challenge and promise lies in unfolding this complex regulation, as this will provide leads for new therapeutic opportunities.

Hypothermia-Induced Loss of Endothelial Barrier Function Is Restored after Dopamine Pretreatment: Role of p42/p44 Activation

2006 ◽  
Vol 82 (4) ◽  
pp. 534-542 ◽  
Author(s):  
Paul-Thomas Brinkkoetter ◽  
Grietje C. Beck ◽  
Uwe Gottmann ◽  
Ralf Loesel ◽  
Ulf Schnetzke ◽  
...  
Keyword(s):  
Barrier Function ◽  
Endothelial Barrier ◽  
Endothelial Barrier Function

scholarly journals Role of Calcium Signaling in Endothelial Barrier Function

2014 ◽  
Vol 106 (2) ◽  
pp. 719a-720a
Author(s):  
Judith A. Stolwijk ◽  
Christian W. Renken ◽  
Mohamed Trebak
Keyword(s):  
Calcium Signaling ◽  
Barrier Function ◽  
Endothelial Barrier ◽  
Endothelial Barrier Function

Glucosylation of small GTP-binding Rho proteins disrupts endothelial barrier function

1997 ◽  
Vol 272 (1) ◽  
pp. L38-L43 ◽  
Author(s):  
S. Hippenstiel ◽  
S. Tannert-Otto ◽  
N. Vollrath ◽  
M. Krull ◽  
I. Just ◽  
...  
Keyword(s):  
Barrier Function ◽  
Endothelial Permeability ◽  
Endothelial Barrier ◽  
Dependent Manner ◽  
Rho Proteins ◽  
Filamentous Actin ◽  
Endothelial Barrier Function ◽  
Gtp Binding ◽  
Escherichia Coli Hemolysin

The endothelial cytoskeleton is important for the regulation of endothelial barrier function. Small GTP-binding Rho proteins play a central role in the organization of the microfilament system. Clostridium difficile toxin B (TcdB) inactivates Rho proteins by glucosylation at Thr-37. We used TcdB as a probe to study the role of Rho proteins in the regulation of endothelial barrier function. TcdB time (50-170 min) and dose (10-100 ng/ml) dependently increased the hydraulic conductivity of cultured porcine pulmonary artery endothelial cell monolayers approximately 10-fold. Simultaneously, the albumin reflection coefficient decreased substantially from 0.8 to 0.15. Before endothelial hyperpermeability, TcdB reduced F-actin content in a dose-dependent manner, whereas G-actin content remained unchanged. Finally, we proved that TcdB caused dose (5-100 ng/ml)- and time-dependent glucosylation of Rho proteins in endothelial cells. Phalloidin, which stabilizes filamentous actin, prevented the effect of TcdB on endothelial permeability. In contrast to thrombin-, hydrogen peroxide-, or Escherichia coli hemolysin-induced hyperpermeability, the elevation of cyclic nucleotides did not block TcdB-related permeability. The data demonstrate a central role of small GTP-binding Rho proteins for the control of endothelial barrier function.

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