scholarly journals Exchange Protein Directly Activated by cAMP Modulates Ebola Virus Uptake into Vascular Endothelial Cells

Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 563 ◽  
Author(s):  
Aleksandra Drelich ◽  
Barbara Judy ◽  
Xi He ◽  
Qing Chang ◽  
Shangyi Yu ◽  
...  

Members of the family Filoviridae, including Ebola virus (EBOV) and Marburg virus (MARV), cause severe hemorrhagic fever in humans and nonhuman primates. Given their high lethality, a comprehensive understanding of filoviral pathogenesis is urgently needed. In the present studies, we revealed that the exchange protein directly activated by cAMP 1 (EPAC1) gene deletion protects vasculature in ex vivo explants from EBOV infection. Importantly, pharmacological inhibition of EPAC1 using EPAC-specific inhibitors (ESIs) mimicked the EPAC1 knockout phenotype in the ex vivo model. ESI treatment dramatically decreased EBOV infectivity in both ex vivo vasculature and in vitro vascular endothelial cells (ECs). Furthermore, postexposure protection of ECs against EBOV infection was conferred using ESIs. Protective efficacy of ESIs in ECs was observed also in MARV infection. Additional studies using a vesicular stomatitis virus pseudotype that expresses EBOV glycoprotein (EGP-VSV) confirmed that ESIs reduced infection in ECs. Ultrastructural studies suggested that ESIs blocked EGP-VSV internalization via inhibition of macropinocytosis. The inactivation of EPAC1 affects the early stage of viral entry after viral binding to the cell surface, but before early endosome formation, in a phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-dependent manner. Our study delineated a new critical role of EPAC1 during EBOV uptake into ECs.

2021 ◽  
Author(s):  
Yi-Ting Yeh ◽  
Danielle E. Skinner ◽  
Ernesto Criado-Hidalgo ◽  
Natalie Shee Chen ◽  
Antoni Garcia-De Herreros ◽  
...  

AbstractThe eggs of the parasitic blood fluke, Schistosoma, are the main drivers of the chronic pathologies associated with schistosomiasis, a disease of poverty afflicting approximately 220 million people worldwide. Eggs laid by Schistosoma mansoni in the bloodstream of the host are encapsulated by vascular endothelial cells (VECs), the first step in the migration of the egg from the blood stream into the lumen of the gut and eventual exit from the body. The biomechanics associated with encapsulation and extravasation of the egg are poorly understood. We demonstrate that S. mansoni eggs induce VECs to form two types of membrane extensions during encapsulation; filopodia that probe eggshell surfaces and intercellular nanotubes that presumably facilitate VEC communication. Encapsulation efficiency, the number of filopodia and intercellular nanotubes, and the length of these structures depend on the egg’s vitality and, to a lesser degree, its maturation state. During encapsulation, live eggs induce VEC contractility and membranous structures formation, in a Rho/ROCK pathway-dependent manner. Using elastic hydrogels embedded with fluorescent microbeads as substrates to culture VECs, live eggs induce VECs to exert significantly greater contractile forces during encapsulation than dead eggs, which leads to 3D deformations on both the VEC monolayer and the flexible substrate underneath. These significant mechanical deformations cause the VEC monolayer tension to fluctuate with eventual rupture of VEC junctions, thus facilitating egg transit out of the blood vessel. Overall, our data on the mechanical interplay between host VECs and the schistosome egg improve our understanding of how this parasite manipulates its immediate environment to maintain disease transmission.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Purum Kang ◽  
Seung Ho Han ◽  
Hea Kyung Moon ◽  
Jeong-Min Lee ◽  
Hyo-Keun Kim ◽  
...  

The purpose of the present study is to examine the effects of essential oil ofCitrus bergamiaRisso (bergamot, BEO) on intracellular Ca2+in human umbilical vein endothelial cells. Fura-2 fluorescence was used to examine changes in intracellular Ca2+concentration[Ca2+]i. In the presence of extracellular Ca2+, BEO increased[Ca2+]i, which was partially inhibited by a nonselective Ca2+channel blocker La3+. In Ca2+-free extracellular solutions, BEO increased[Ca2+]iin a concentration-dependent manner, suggesting that BEO mobilizes intracellular Ca2+. BEO-induced[Ca2+]iincrease was partially inhibited by a Ca2+-induced Ca2+release inhibitor dantrolene, a phospholipase C inhibitor U73122, and an inositol 1,4,5-triphosphate (IP3)-gated Ca2+channel blocker, 2-aminoethoxydiphenyl borane (2-APB). BEO also increased[Ca2+]iin the presence of carbonyl cyanide m-chlorophenylhydrazone, an inhibitor of mitochondrial Ca2+uptake. In addition, store-operated Ca2+entry (SOC) was potentiated by BEO. These results suggest that BEO mobilizes Ca2+from primary intracellular stores via Ca2+-induced and IP3-mediated Ca2+release and affect promotion of Ca2+influx, likely via an SOC mechanism.


2009 ◽  
Vol 102 (08) ◽  
pp. 352-359 ◽  
Author(s):  
Haichao Wang ◽  
Yiting Tang ◽  
Zhang Fan ◽  
Ben Lv ◽  
Xianzhong Xiao ◽  
...  

SummaryHigh-mobility group box 1 protein (HMGB1), an abundant nuclear protein, was recently established as a proinflammatory mediator of experimental sepsis.Although extracellular HMGB1 has been found in atherosclerotic plaques, its potential role in the pathogenesis of atherothrombosis remains elusive. In the present study, we determined whether HMGB1 induces tissue factor (TF) expression in vascular endothelial cells (ECs) and macrophages. Our data showed that HMGB1 stimulated ECs to express TF (but not TF pathway inhibitor) mRNA and protein in a concentration and time-dependent manner. Blockade of cell surface receptors (including TLR4, TLR2, and RAGE) with specific neutralising antibodies partially reduced HMGB1-induced TF expression. Moreover, HMGB1 increased expression of Egr-1 and nuclear translocation of NF-κB (c-Rel/p65) in ECs. Taken together, our data suggest that HMGB1 induces TF expression in vascular endothelial cells via cell surface receptors (TLR4, TLR2, and RAGE), and through activation of transcription factors (NF-κB and Egr-1).


2021 ◽  
Author(s):  
hong fang ◽  
Chi liu ◽  
Omer Cavdar ◽  
Yi Shen

Abstract PurposeTo verify the effect of Angiotensin II on ferroptosis in vascular endothelial cells and clarify the related mechanism. MethodsHUVECs were evaluated for p53, P21,ALOX12, VEGF, MDA,GSH. Molecular marker impact upon AngII-induced ferroptosis was evaluated with students’ t-test,one-way analysis of variance (ANOVA).ResultsAs the concentration of Ang II increased,the level of ALOX12, P53,GSH and MDA increased in HUVECs. The expression of VEGFA in HUVECs is negatively correlated with dose of Ang II. Incubation of HUVECs in AngII and valsartan for 48hr reduces ALOX12, P21, GSH and MDA. Compared with the single AngII group, ALOX12, P21, GSH and MDA in valsartan group was decreased significantly(p=0.000).In pifithrin-α hydrobromide-treated, ALOX12, P21, GSH and MDA was reduced significantly, as compared to valsartan group(p=0.000). The most larger reduction in ALOX12, P21,GSH and MDA was pifithrin - α hydrobromide combined with valsartan group. In contrast, the expression of VEGFA increased significantly after HUVECs were treated with pifithrin - α hydrobromide and valsartan(p=0.000).ConclusionsAngII can induce ferroptosis of vascular endothelial cells in a dose-dependent manner. The mechanism of AngII-induced ferroptosis may be regulated through the signal axis of ATR1,2-p53-ALOX12.


1998 ◽  
Vol 80 (12) ◽  
pp. 1008-1041 ◽  
Author(s):  
Matthias Kalbas ◽  
Antje Willuweit ◽  
Volker Henn ◽  
Richard Kroczek ◽  
Gert Müller-Berghaus ◽  
...  

SummaryCD40 is a type I member of the tumour necrosis factor (TNF) receptor superfamily of proteins, and is present on a wide variety of cells including vascular endothelial cells. Ligation of this receptor on endothelial cells is known to increase expression of inflammatory adhesion molecules. We have recently demonstrated that platelets express the ligand of CD40 (CD154) within seconds of exposure to agonist, and interact with endothelial cells to participate directly in the induction of an inflammatory response. Here we show that activated platelets induce tissue factor (TF) expression on endothelial cells in a CD40/CD154-dependent manner, and that the magnitude of this response can equal that induced by TNFα. Moreover, CD40 ligation on endothelial cells downregulates the expression of thrombomodulin. We also show that CD40-mediated TF expression is less sensitive to inhibition with the oxidative radical scavenger pyrrolidine dithiocarbamate than is that mediated by TNFα, indicating that CD40 has a distinct signalling pathway. Tissue factor is a cell membrane protein which functions as the main trigger of the extrinsic pathway of blood coagulation, and its expression on endothelial cells is implicated in wound healing and angiogenesis. Since platelets are among the first cells involved in haemostasis following tissue injury, our data showing that ligation of CD40 by CD154 induces a procoagulant phenotype on vascular endothelial cells suggests that platelets may play an important role in the induction of wound healing.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Changyou Li ◽  
Siyuan Li ◽  
Changkai Jia ◽  
Lingling Yang ◽  
Zicheng Song ◽  
...  

Previous studies showed that several members of the S100A family are involved in neovascularization and tumor development. This study checked whether low concentrations of S100A8 or S100A9 has any effect on the behaviour of vascular endothelial cells. A human umbilical vascular endothelial cell (HUVEC) line was used to measure vascular endothelial cell bioactivity related to angiogenesis, such as cell proliferation, migration, and vessel formation. In the low concentration range up to 10 μg/mL, either each alone or in combination, S100A8 and S100A9 proteins promoted proliferation of HUVEC cells in a dose-dependent manner. The presence of both proteins in culture showed additive effects over each single protein. Both proteins enhanced HUVEC cells to migrate across the transwell membrane and to form tube-like structures on the Matrigel surface. When mixed in Matrigel and injected subcutaneously in Balb/c mice, both proteins increased vessel development in the gel plugs. Microarray assay of HUVEC cells treated with 10 μg/mL S100A8 revealed that ribosome pathway, pathogenicEscherichia coliinfection pathway, apoptosis, and stress response genes were modulated by S100A8 treatment. We propose that S100A8 and S100A9 proteins from either infiltrating inflammatory cells or tumor cells play an important role in the interplay among inflammation, angiogenesis, and tumorigenesis.


Blood ◽  
2011 ◽  
Vol 118 (11) ◽  
pp. 3182-3185 ◽  
Author(s):  
Yuko Suzuki ◽  
Hideki Yasui ◽  
Tomasz Brzoska ◽  
Hideo Mogami ◽  
Tetsumei Urano

Abstract In a previous study, we demonstrated unique secretory dynamics of tissue plasminogen activator (tPA) in which tPA was retained on the cell surface in a heavy chain–dependent manner after exocytosis from secretory granules in vascular endothelial cells. Here, we examined how retained tPA expresses its enzymatic activity. Retained tPA effectively increased the lysine binding site–dependent binding of plasminogen on the cell surface and pericellular area; this was abolished by inhibition of enzymatic activity of either tPA or plasmin, which suggests that de novo generation of carboxyl-terminal lysine as a consequence of degradation of surface/pericellular proteins by plasmin is essential. Retained tPA initiated zonal clot lysis of a fibrin network that had been formed on vascular endothelial cells, which was preceded by the binding of plasminogen to the lysis front. Our results provide evidence that secreted and retained tPA is essential for maintaining both high fibrinolytic activity and effective clot lysis on the vascular endothelial cell surface.


Sign in / Sign up

Export Citation Format

Share Document