scholarly journals Loss of Endothelial Barrier Function in the Inflammatory Setting: Indication for a Cytokine-Mediated Post-Transcriptional Mechanism by Virtue of Upregulation of miRNAs miR-29a-3p, miR-29b-3p, and miR-155-5p

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2843
Author(s):  
Daniel Maucher ◽  
Birte Schmidt ◽  
Julia Schumann

Dysfunction of the endothelial barrier plays a central role in the pathogenesis of both acute and chronic inflammatory processes such as sepsis or atherosclerosis. Due to attenuation of endothelial cell contacts, there is an increased transfer of blood proteins and fluid into the surrounding tissue, which relates to edema formation and distribution disorders. However, the mechanisms underlying these responses are not fully understood. In this study, we used human endothelial cells to mimic the loss of barrier function in an inflammatory milieu. We found that a weakened endothelial barrier after cytokine stimulation was accompanied by a significantly changed transcriptome. Apparent was a depletion of mRNAs encoding cell adhesion molecules. Furthermore, we found that cytokine treatment of endothelial cells induced upregulation of miR-29a-3p, miR-29b-3p, and miR-155-5p. miRNAs are known to negatively affect stability and translational efficiency of target mRNAs. Remarkably, miR-29a-3p, miR-29b-3p, and miR-155-5p have already been described to target the mRNAs of central tight and adherent junction proteins including F11 receptor, claudin 1, β-catenin, p120-catenin, and eplin. This taken together points to the existence of a posttranscriptional mechanism for expression inhibition of central adhesion proteins, which is triggered by inflammatory cytokines and mediated by miR-29a-3p, miR-29b-3p, and miR-155-5p.

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
M Aslam ◽  
H Idrees ◽  
C W Hamm ◽  
Y Ladilov

Abstract Background The integrity of the endothelial cell barrier of the microvasculature is compromised by inflammation. The increased vascular permeability leads to tissue injury and organ dysfunction. In recent years, considerable advances have been made in the understanding of signalling mechanisms regulating the endothelial barrier integrity. The role of endothelial metabolism as a modulator of endothelial barrier integrity is not yet well-studied. The aim of the present study was to investigate the effect of inflammation on endothelial metabolism and its role in the maintenance of endothelial barrier integrity. Methods The study was carried out on cultured human umbilical vein endothelial cells and rat coronary microvascular endothelial cells. Inflammatory condition was simulated by treating cells with low concentrations (1 ng/mL) of TNFα for 24h. Endothelial barrier function was analysed by measuring the flux of albumen through endothelial monolayers cultured on filter membranes. Gene expression was analysed by qPCR-based assays. The capacity of endothelial cells for maximal ATP synthesis rate was investigated by the real-time live-cell imaging using FRET-based ATP-biosensor (live cell FRET). Total cellular ATP concentration was measured using luminescence-based commercial kit (ATPLite, PerkinElmer). Mitochondrial mass was analysed by the ratio of mitochondrial DNA (mtDNA) to nuclear DNA (nDNA). The cellular glucose uptake was measured by fluorescent microscopy using a fluorescent analogue of glucose (2-NBDG). Results Treatment of human endothelial cells with TNFα resulted in significant suppression of mitochondrial and upregulation of glycolytic ATP synthesis rate, suggesting a metabolic switch. This was accompanied by a reduction in mitochondrial content (mtDNA/nDNA), reduction in total cellular ATP levels, an enhanced expression of glycolytic enzymes 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) and phosphofructokinase 1 (PFK1), and enhanced glucose uptake by endothelial cells (n=5; p<0.05 for all parameters tested). Moreover, TNFα caused a 3-fold increase in endothelial permeability. Pharmacological inhibition of glycolysis either by partial replacement of glucose with 2-deoxy glucose (2DG) or an inhibition of PFKFB3 resulted in further worsening (a 5-fold increase in permeability) of TNFα-induced endothelial barrier failure. On the other hand pharmacological activation of AMPK, a potent inducer of mitochondrial biogenesis, could attenuate TNFα-induced but not 2DG-induced endothelial hyperpermeability. Conclusion The study demonstrates that TNFα induces metabolic switch towards glycolysis in endothelial cells. Moreover, the data suggest that upregulation of glycolysis may serve as an endogenous metabolic adaptation to the TNFα-induced suppression of mitochondrial ATP synthesis, which protects endothelial barrier integrity. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Justus-Liebig University GiessenDZHK (German Centre for Cardiovascular Research), partner site Rhein-Main, Bad Nauheim, Germany


2019 ◽  
Vol 30 (5) ◽  
pp. 607-621 ◽  
Author(s):  
Manon C. A. Pronk ◽  
Jisca Majolée ◽  
Anke Loregger ◽  
Jan S. M. van Bezu ◽  
Noam Zelcer ◽  
...  

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.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
L O N G Wang ◽  
W E N Kang ◽  
Y U E Cheng ◽  
X I Wang

Abstract Background The main path of sepsis-induced cardiomyopathy is the loss of endothelial barrier function. Neuregulin-1 (NRG-1) has beneficial effects on endothelial function. Purpose To investigate the effect of NRG-1 treatment on the protection of cardiac endothelial cells and the changes of RhoA/ROCK signaling in sepsis. Methods Rats were randomly divided into three groups: sham, LPS, and NRG-1. After successful induction of sepsis by lipopolysaccharide (LPS, 10mg/kg), rats were administered either a vehicle or recombinant human neuregulin-1 (rhNRG-1, 10μg/kg/d) for one or two days. We recorded their survival rate at 48h after sepsis. Hemodynamic methods were performed to assess cardiac function. We used immunofluorescence assay to detect von Willebrand Factor (vWF). Intercellular adhesion molecule-1 (ICAM-1) and vascular endothelial growth factor (VEGF)levels in serum were measured by enzyme-linked immunosorbent assay (ELISA), and serum nitric oxide (NO) was detected by reductase method. We used transmission electron microscopy to observe changes in myocardial ultrastructure and western blot to assess expression of RhoA and ROCK1 protein. Results Sepsis impaired endothelial function manifested by increased ICAM-1, NO and VEGF levels in serum, NRG-1 treatment could significantly alleviate these increase (P<0.05). Compared with the vehicle, NRG-1 significantly decreased cardiac vascular permeability through increasing the expression of vWF on endothelial lining (P<0.05). Moreover, NRG-1 alleviated damages of ultrastructure of myocardial cells and suppressed the expression of RhoA and ROCK1 protein (P<0.05). Ultimately, NRG-1 improved the survival,and prevented hemodynamic derangement. Levels of endothelial biomarker in serum ICAM-1 (pg/ml) VEGF (pg/ml) NO (pg/ml) Sham 24h 1564.74±94.41 0.84±0.28 203.27±1.81 Sham 48h 322.92±7.92 1.78±0.61 6.57±0.38 LPS 24h 5139.85±284.15† 3.11±0.04† 679.05±78.59† LPS 48h 950.41±25.23†‡ 4.65±0.30† 180.40±30.08†‡ NRG 24h 2772.18±164.45§ 0.30±0.04§ 355.14±23.41§ NRG 48h 578.57±28.97§‡ 1.02±0.45§ 104.67±2.13§‡ †p<0.05 vs. the sham group, §p<0.05 vs. the LPS group and ‡p<0.05 vs. the 24h group. Effect of NRG-1 on endothelial cells Conclusions NRG-1 could alleviate endothelial injury in sepsis by strengthening the barrier function of vascular, reducing the secretion of endothelial-related biomarkers and inhibiting oxidative stress, thus improving cardiac function and survival rate, these effects may base on RhoA/ROCK signaling pathway. These may contribute to reverse the impaired endothelial cells in sepsis in the future. Acknowledgement/Funding The national natural science foundation of China (81772044)


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.


2021 ◽  
Author(s):  
Stefanie Deinhardt-Emmer ◽  
Sarah Böttcher ◽  
Clio Häring ◽  
Liane Giebeler ◽  
Andreas Henke ◽  
...  

Infections with SARS-CoV-2 can be asymptomatic, but they can also be accompanied by a variety of symptoms that result in mild to severe coronavirus disease-19 (COVID-19) and are sometimes associated with systemic symptoms. Although the viral infection originates in the respiratory system, it is unclear how the virus can overcome the alveolar barrier, which is observed in severe COVID-19 disease courses. To elucidate the viral effects on the barrier integrity and immune reactions, we used mono-cell culture systems and a complex human chip model composed of epithelial, endothelial, and mononuclear cells. Our data show that SARS-CoV-2 efficiently infected epithelial cells with high viral loads and inflammatory response, including interferon expression. By contrast, the adjacent endothelial layer was neither infected nor did it show productive virus replication or interferon release. With prolonged infection, both cell types were damaged, and the barrier function was deteriorated, allowing the viral particles to overbear. In our study, we demonstrate that although SARS-CoV-2 is dependent on the epithelium for efficient replication, the neighboring endothelial cells are affected, e.g., by the epithelial cytokines or components induced during infection, which further results in the damage of the epithelial/endothelial barrier function and viral dissemination. IMPORTANCE SARS-CoV-2 challenges healthcare systems and societies worldwide in unprecedented ways. Although numerous new studies have been conducted, research to better understand the molecular pathogen-host interactions are urgently needed. For this, experimental models have to be developed and adapted. In the present study we used mono cell-culture systems and we established a complex chip model, where epithelial and endothelial cells are cultured in close proximity. We demonstrate that epithelial cells can be infected with SARS-CoV-2, while the endothelium did not show any infection signs. Since SARS-CoV-2 is able to establish viremia, the link to thromboembolic events in severe COVID-19 courses is evident. However, whether the endothelial layer is damaged by the viral pathogens or whether other endothelial-independent homeostatic factors are induced by the virus is essential for understanding the disease development. Therefore, our study is important as it demonstrates that the endothelial layer could not be infected by SARS-CoV-2 in our in vitro experiments, but we were able to show the destruction of the epithelial-endothelial barrier in our chip model. From our experiments we can assume that virus-induced host factors disturbed the epithelial-endothelial barrier function and thereby promote viral spread.


Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2170
Author(s):  
Alexander García-Ponce ◽  
Katharina Schuster ◽  
Stein-Ove Døskeland ◽  
Rolf K. Reed ◽  
Fitz-Roy E. Curry ◽  
...  

Epac1 (exchange protein activated by cAMP) stabilizes the endothelial barrier, but detailed studies are limited by the side effects of pharmacological Epac1 modulators and transient transfections. Here, we compare the key properties of barriers between endothelial cells derived from wild-type (WT) and Epac1-knockout (KO) mice myocardium. We found that KO cell layers, unlike WT layers, had low and cAMP-insensitive trans-endothelial resistance (TER). They also had fragmented VE-cadherin staining despite having augmented cAMP levels and increased protein expression of Rap1, Rac1, RhoA, and VE-cadherin. The simultaneous direct activation of Rac1 and RhoA by CN04 compensated Epac1 loss, since TER was increased. In KO-cells, inhibition of Rac1 activity had no additional effect on TER, suggesting that other mechanisms compensate the inhibition of the Rac1 function to preserve barrier properties. In summary, Epac1 is crucial for baseline and cAMP-mediated barrier stabilization through mechanisms that are at least partially independent of Rac1.


2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Maura Knapp ◽  
Mei Zheng ◽  
Nikola Sladojevic ◽  
Qiong Zhao ◽  
Konstaintin G Birukov ◽  
...  

Background: Diabetes leads to endothelial barrier dysfunction and altered endothelial permeability, which results in increased cardiovascular risk. ARNT, also known as HIF-1β, a transcription factor that functions as a master regulator of glucose homeostasis, has been implicated in diabetes. Endothelial-specific ARNT deletion (ArntΔEC) in mice is embryonically lethal, with hemorrhage occurring in the heart during the embryonic stage. However, the particular role of endothelial ARNT(ecARNT) in diabetes is largely unknown. We have found a significant decrease in ARNT expression in both diabetic rodent endothelial cells and diabetic human hearts. We hypothesize that a loss of ecARNT mediates endothelial barrier dysfunction during diabetes. Methods and Results: We generated inducible endothelial specific ARNT knockout mice (ecARNT-/-) by crossing mice with loxP sequences flanking exon 6 of ARNT with Cre ERT2 mice under the VE-cadherin promoter. A 90% deletion of ecARNT was achieved following two weeks of oral tamoxifen administration. ecARNT-/- mice exhibit severe blood vessel leakage, which is restricted to the heart, suggesting a distinct function for ecARNT in different tissues. Cardiomyopathy is evident 6 months after ARNT deletion. In vitro , trans-endothelial electrical resistance (TER) and transwell assays have confirmed endothelial barrier disruption in cardiac microvascular endothelial cells (CMEC) isolated from both ecARNT-/- hearts and diabetic (DB/DB) mouse hearts. To determine the underlying mechanisms by which ARNT may regulate endothelial barrier function, we performed DNA sequencing on CMEC isolated from control, ecARNT-/-, and DB/DB mice. Data suggest a significant increase in TNFa signaling, including ELAM-1 and ICAM-1 in CMEC isolated from ecARNT-/- CMEC and diabetic CMEC. Moreover, use of anti-TNFa antibody rescues endothelial barrier dysfunction in CMEC isolated from ecARNT-/- mice. Taken together, these results suggest that a reduction in ecARNT during diabetes may mediate endothelial barrier dysfunction through a TNFa signaling pathway. Conclusion: ecARNT is a critical mediator of endothelial barrier function and could potentially serve as a therapeutic target for diabetic cardiovascular diseases.


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)


Sign in / Sign up

Export Citation Format

Share Document