scholarly journals Hepatic sinusoidal endothelium avidly binds platelets in an integrin-dependent manner, leading to platelet and endothelial activation and leukocyte recruitment

2013 ◽  
Vol 304 (5) ◽  
pp. G469-G478 ◽  
Author(s):  
Patricia F. Lalor ◽  
John Herbert ◽  
Roy Bicknell ◽  
David H. Adams
Keyword(s):  
Endothelial Cells ◽  
Liver Injury ◽  
Leukocyte Adhesion ◽  
Endothelial Activation ◽  
Dependent Manner ◽  
Hepatic Sinusoid ◽  
Public Expression ◽  
Platelet Binding ◽  
Sinusoidal Endothelium ◽  
Functional Relevance

Platelets have recently been shown to drive liver injury in murine models of viral hepatitis and promote liver regeneration through the release of serotonin. Despite their emerging role in inflammatory liver disease, little is known about the mechanisms by which platelets bind to the hepatic vasculature. Therefore, we referenced public expression data to determine the profile of potential adhesive receptors expressed by hepatic endothelium. We then used a combination of tissue-binding and flow-based endothelial-binding adhesion assays to show that resting platelets bind to human hepatic sinusoidal endothelial cells and that the magnitude of adhesion is greatly enhanced by thrombin-induced platelet activation. Adhesion was mediated by the integrins Gp1b, αIIbβIII, and αvβ3, as well as immobilized fibrinogen. Platelet binding to hepatic endothelial cells resulted in NF-κB activation and increased chemokine secretion. The functional relevance of platelet binding was confirmed by experiments that showed markedly increased binding of neutrophils and lymphocytes to hepatic endothelial cells under shear conditions replicating those found in the hepatic sinusoid, which was in part dependent on P-selectin expression. Thus the ability of platelets to activate endothelium and promote leukocyte adhesion may reflect an additional mechanism through which they promote liver injury.

scholarly journals Effects of TNF-α on Leukocyte Adhesion Molecule Expressions in Cultured Human Lymphatic Endothelium

2007 ◽  
Vol 55 (7) ◽  
pp. 721-733 ◽  
Author(s):  
Yoshihiko Sawa ◽  
Yukitaka Sugimoto ◽  
Takeshi Ueki ◽  
Hiroyuki Ishikawa ◽  
Atuko Sato ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Adhesion ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Leukocyte Adhesion ◽  
Dependent Manner ◽  
Lymphatic Endothelium ◽  
Leukocyte Adhesion Molecule ◽  
Tnf Α ◽  
Cell Adhesion Molecule 1

TNF-α alters leukocyte adhesion molecule expression of cultured endothelial cells like human umbilical vein endothelial cells (HUVEC). This study was designed to investigate the changes in vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and platelet endothelial cell adhesion molecule-1 (PECAM-1) expression with TNF-α stimulation in cultured human neonatal dermal lymphatic endothelial cells (HNDLEC). The real-time quantitative PCR analysis on HNDLEC showed that TNF-α treatment leads to increases of VCAM-1 and ICAM-1 mRNAs to the 10.8- and 48.2-fold levels of untreated cells and leads to a reduction of PECAM-1 mRNA to the 0.42-fold level of untreated cells. Western blot and immunohistochemical analysis showed that TNF-α leads to VCAM-1 and ICAM-1 expressions that were inhibited by antiserum to human TNF receptor or by AP-1 inhibitor nobiletin. In flow cytometry analysis, the number of VCAM-1- and ICAM-1-positive cells increased, and PECAM-1-positive cells decreased with TNF-α treatment. Regarding protein amounts produced in cells and amounts expressed on the cell surface, VCAM-1 and ICAM-1 increased in HNDLEC and HUVEC, and PECAM-1 decreased in HNDLEC in a TNF-α concentration-dependent manner. VCAM-1, ICAM-1, and PECAM-1 protein amounts in TNF-α-stimulated cells were lower in HNDLEC than in HUVEC. This suggests that the lymphatic endothelium has the TNF-α-induced signaling pathway, resulting in increased VCAM-1 and ICAM-1 expression to a weaker extent than blood endothelium and PECAM-1 reduction to a stronger extent than blood endothelium.

Abstract 378: Contribution of Unfolded Protein Response in Arsenic-Induced Endothelial Activation and Atherosclerois

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Srinivas D Sithu ◽  
Nalinie S Wickramasinghe ◽  
Elena Vladykovskaya ◽  
Petra Haberzettl ◽  
Abhinav Agarwal ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Folding ◽  
Leukocyte Adhesion ◽  
Endothelial Activation ◽  
Aortic Endothelial Cells ◽  
Unfolded Protein ◽  
Atherosclerotic Lesions ◽  
Endothelial Migration ◽  
Nf Kappab ◽  
Protein Response

Epidemiological and animal studies suggest that exposure to arsenic contaminated water exacerbates atherosclerosis. However, the mechanisms by which arsenic exerts its atherogenic effects are not known. We observed that chronic (1 μM; 4 days) or acute (20 μM; 2-6 hours) exposure of sodium arsenite to human umbilical vein endothelial cells (HUVEC) increased the surface expression of adhesion molecules ICAM-1, VCAM-1 and E-Selectin by 1.2-1.5-fold; leukocyte adhesion by 1.5-3.5 fold; leukocyte trans-endothelial migration by 1.7-2.5-fold; and mRNA expression of IL-8 by 5-25-fold. Similarly, exposure of human aortic endothelial cells and mouse aortic endothelial cells to arsenic also caused endothelial activation. Arsenic also enhanced the unfolded protein response (UPR) in endothelial cells as evident by the phosphorylation of IRE-1 and activation of its downstream proteins JNK and NF-kappaB; nuclear translocation of ATF6, and increased expression of molecular chaperones GRP78 and HERP. SiRNA-mediated knockdown of IRE-1 attenuated arsenic-induced NF-kappaB activation and IL-8 expression, but did not affect JNK phosphorylation. Adenoviral transfection with ATF-6 upregulated GRP78 and decreased the expression of IL-8. Similarly, pre-incubation of endothelial cells with phenyl butyric acid (PBA; 5 mM, 16h), a chemical chaperone of protein folding, significantly (P<0.05) prevented arsenic-induced leukocyte adhesion, trans-endothelial migration and IL-8 expression. Feeding of apoE-null mice with PBA for 16 weeks inhibited the arsenic-induced UPR in atherosclerotic lesions; expression of adhesion molecules on endothelial cells lining the atherosclerotic lesions; lesional and systemic inflammation; and prevented the arsenic-induced exacerbation of lesion formation by 90% (P<0.05). Together, these data suggest that arsenic causes endothelial activation and exacerbates atherosclerosis by triggering UPR and chemical chaperones of protein folding prevent arsenic-induced exacerbation of atherogenesis.

Antiendothelial cell antibodies mediate enhanced leukocyte adhesion to cytokine-activated endothelial cells through a novel mechanism requiring cooperation between FcγRIIa and CXCR1/2

Blood ◽  
2007 ◽  
Vol 109 (9) ◽  
pp. 3881-3889 ◽  
Author(s):  
Oliver J. Florey ◽  
Michael Johns ◽  
Olubukola O. Esho ◽  
Justin C. Mason ◽  
Dorian O. Haskard
Keyword(s):  
Endothelial Cells ◽  
Lupus Erythematosus ◽  
Immune Complexes ◽  
Neutralizing Antibodies ◽  
Inflammatory Responses ◽  
Tissue Injury ◽  
Leukocyte Adhesion ◽  
Dependent Manner ◽  
Wegener Granulomatosis ◽  
Necessary And Sufficient

Abstract Antiendothelial cell antibodies (AECAs) are commonly detectable in diseases associated with vascular injury, including systemic lupus erythematosus (SLE), systemic sclerosis, Takayasu arteritis, Wegener granulomatosis, Behçet syndrome, and transplant arteriosclerosis. Here, we explore the hypothesis that these antibodies might augment polymorphonuclear leukocyte (PMN) adhesion to endothelium in inflammation. Initially, we established that a mouse IgG mAb bound to endothelial cells (ECs) significantly increased PMN adhesion to cytokine-stimulated endothelium in an FcγRIIa-dependent manner. Neutralizing antibodies, and adenoviral transduction of resting ECs, demonstrated that the combination of E-selectin, CXCR1/2, and β2 integrins is both necessary and sufficient for this process. We observed an identical mechanism using AECA IgG isolated directly from patients with SLE. Assembled immune complexes also enhanced PMN adhesion to endothelium, but, in contrast to adhesion because of AECAs, this process did not require CXCR1/2, was not inhibited by pertussis toxin, and was FcγRIIIb rather than FcγRIIa dependent. These data are the first to demonstrate separate nonredundant FcγRIIa and FcγRIIIb-mediated mechanisms by which EC-bound monomeric IgG and assembled immune complexes amplify leukocyte adhesion under dynamic conditions. Furthermore, the observation that FcγRIIa and CXCR1/2 cooperate to enhance PMN recruitment in the presence of AECAs suggests a mechanism whereby AECAs may augment tissue injury during inflammatory responses.

scholarly journals Endothelial cell activation by antiphospholipid antibodies is modulated by Krüppel-like transcription factors

Blood ◽  
2011 ◽  
Vol 117 (23) ◽  
pp. 6383-6391 ◽  
Author(s):  
Kristi L. Allen ◽  
Anne Hamik ◽  
Mukesh K. Jain ◽  
Keith R. McCrae
Keyword(s):  
Endothelial Cells ◽  
Antiphospholipid Antibodies ◽  
Transcriptional Activity ◽  
Cell Activation ◽  
Critical Role ◽  
Endothelial Activation ◽  
Dependent Manner ◽  
Endothelial Cell Activation ◽  
Proinflammatory Response ◽  
Endothelial Response

Abstract Antiphospholipid syndrome is characterized by thrombosis and/or recurrent pregnancy loss in the presence of antiphospholipid antibodies (APLAs). The majority of APLAs are directed against phospholipid-binding proteins, particularly β2-glycoprotein I (β2GPI). Anti-β2GPI antibodies activate endothelial cells in a β2GPI-dependent manner through a pathway that involves NF-κB. Krüppel-like factors (KLFs) play a critical role in regulating the endothelial response to inflammatory stimuli. We hypothesized that activation of endothelial cells by APLA/anti-β2GPI antibodies might be associated with decreased expression of KLFs, which in turn might facilitate cellular activation mediated through NF-κB. Our experimental results confirmed this hypothesis, demonstrating markedly decreased expression of KLF2 and KLF4 after incubation of cells with APLA/anti-β2GPI antibodies. Restoration of KLF2 or KLF4 levels inhibited NF-κB transcriptional activity and blocked APLA/anti-β2GPI–mediated endothelial activation despite NF-κB p65 phosphorylation. Chromatin immunoprecipitation analysis demonstrated that inhibition of NF-κB transcriptional activity by KLFs reflects sequestration of the cotranscriptional activator CBP/p300, making this cofactor unavailable to NF-κB. These findings suggest that the endothelial response to APLA/anti-β2GPI antibodies reflects competition between KLFs and NF-κB for their common cofactor, CBP/p300. Taken together, these observations are the first to implicate the KLFs as novel participants in the endothelial proinflammatory response to APLA/anti-β2GPI antibodies.

Leukocyte-platelet aggregate adhesion and vascular permeability in intact microvessels: role of activated endothelial cells

2006 ◽  
Vol 291 (2) ◽  
pp. H591-H599 ◽  
Author(s):  
Pingnian He ◽  
Hong Zhang ◽  
Longkun Zhu ◽  
Yanyan Jiang ◽  
Xueping Zhou
Keyword(s):  
Endothelial Cells ◽  
Tissue Injury ◽  
Leukocyte Adhesion ◽  
Single Cells ◽  
Autologous Blood ◽  
Blood Perfusion ◽  
Endothelial Activation ◽  
Confocal Imaging ◽  
Platelet Aggregate ◽  
Microvessel Permeability

Leukocyte-platelet aggregation and aggregate adhesion have been indicated as biomarkers of the severity of tissue injury during inflammation or ischemic reperfusion. The objective of this study is to investigate the mechanisms of the aggregate adhesion and quantitatively evaluate its relationship with microvessel permeability. A combined autologous blood perfusion with single microvessel perfusion technique was employed in rat mesenteric venular microvessels. The aggregate adhesion was induced by systemic application of TNF-α plus local application of platelet-activating factor (PAF). Changes in permeability were determined by measurements of hydraulic conductivity ( Lp) before and after aggregate adhesion in the same individually perfused microvessels. The compositions of the adherent aggregates were identified with fluorescent labeling and confocal imaging. In contrast to leukocyte adhesion as single cells resulting in no increase in microvessel permeability, aggregate adhesion induced prolonged increases in microvessel Lp(6.1 ± 0.9 times the control, n = 9) indicated by the initial Lpmeasurements after 3 h of blood perfusion, which is distinct from the transient Lpincrease caused by PAF-induced endothelial activation in the absence of blood. Isoproteronol (Iso) attenuated aggregate adhesion-mediated Lpincreases if applied after autologous blood perfusion and prevented the aggregate adhesion if the initial endothelial activation is inhibited by applying Iso before PAF administration but showed less effect on single leukocyte adhesion. This study demonstrated that leukocyte-platelet aggregate adhesion via a mechanism different from that of single leukocyte adhesion caused a prolonged increase in microvessel permeability. Our results also indicate that the initial activation of endothelial cells by PAF plays a crucial role in the initiation of leukocyte-platelet aggregate adhesion.

scholarly journals Recombinant Human Soluble Thrombomodulin Suppresses Monocyte Adhesion by Reducing Lipopolysaccharide-Induced Endothelial Cellular Stiffening

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1811
Author(s):  
Takayuki Okamoto ◽  
Eiji Kawamoto ◽  
Haruki Usuda ◽  
Tetsuya Tanaka ◽  
Tetsuro Nikai ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Leukocyte Adhesion ◽  
Adhesion Formation ◽  
Dependent Manner ◽  
Monocyte Adhesion ◽  
Soluble Thrombomodulin ◽  
Force Microscopy ◽  
Actin Fiber ◽  
Result Show ◽  
The Impact

Endothelial cellular stiffening has been observed not only in inflamed cultured endothelial cells but also in the endothelium of atherosclerotic regions, which is an underlying cause of monocyte adhesion and accumulation. Although recombinant soluble thrombomodulin (rsTM) has been reported to suppress the inflammatory response of endothelial cells, its role in regulating endothelial cellular stiffness remains unclear. The purpose of this study was to investigate the impact of anticoagulant rsTM on lipopolysaccharide (LPS)-induced endothelial cellular stiffening. We show that LPS increases endothelial cellular stiffness by using atomic force microscopy and that rsTM reduces LPS-induced cellular stiffening not only through the attenuation of actin fiber and focal adhesion formation but also via the improvement of gap junction functionality. Moreover, post-administration of rsTM, after LPS stimulation, attenuated LPS-induced cellular stiffening. We also found that endothelial cells regulate leukocyte adhesion in a substrate- and cellular stiffness-dependent manner. Our result show that LPS-induced cellular stiffening enhances monocytic THP-1 cell line adhesion, whereas rsTM suppresses THP-1 cell adhesion to inflamed endothelial cells by reducing cellular stiffness. Endothelial cells increase cellular stiffness in reaction to inflammation, thereby promoting monocyte adhesion. Treatment of rsTM reduced LPS-induced cellular stiffening and suppressed monocyte adhesion in a cellular stiffness-dependent manner.

scholarly journals Ebola Virus GP Activates Endothelial Cells via Host Cytoskeletal Signaling Factors

Viruses ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 142
Author(s):  
Benedicte Mpia Moni ◽  
Yasuteru Sakurai ◽  
Jiro Yasuda
Keyword(s):  
Endothelial Cells ◽  
Molecular Mechanisms ◽  
Ebola Virus ◽  
Kinase Inhibitors ◽  
Virus Disease ◽  
Endothelial Activation ◽  
Late Time ◽  
Dependent Manner ◽  
Tnf Α ◽  
Kinetic Pattern

Ebola virus disease (EVD) is a lethal disease caused by the highly pathogenic Ebola virus (EBOV), and its major symptoms in severe cases include vascular leakage and hemorrhage. These symptoms are caused by abnormal activation and disruption of endothelial cells (ECs) whose mediators include EBOV glycoprotein (GP) without the need for viral replication. However, the detailed molecular mechanisms underlying virus–host interactions remain largely unknown. Here, we show that EBOV-like particles (VLPs) formed by GP, VP40, and NP activate ECs in a GP-dependent manner, as demonstrated by the upregulation of intercellular adhesion molecules-1 (ICAM-1) expression. VLPs-mediated ECs activation showed a different kinetic pattern from that of TNF-α-mediated activation and was associated with apoptotic ECs disruption. In contrast to TNF-α, VLPs induced ICAM-1 overexpression at late time points. Furthermore, screening of host cytoskeletal signaling inhibitors revealed that focal adhesion kinase inhibitors were found to be potent inhibitors of ICAM-1 expression mediated by both TNF-α and VLPs. Our results suggest that EBOV GP stimulates ECs to induce endothelial activation and dysfunction with the involvement of host cytoskeletal signaling factors, which represent potential therapeutic targets for EVD.

Antiphospholipid Antibodies Activate Vascular Endothelial Cells

Lupus ◽  
1996 ◽  
Vol 5 (5) ◽  
pp. 440-441 ◽  
Author(s):  
R Simantov ◽  
SK Lo ◽  
A Gharavi ◽  
LR Sammaritano ◽  
JE Salmon ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Antiphospholipid Antibodies ◽  
Vascular Endothelial Cells ◽  
Leukocyte Adhesion ◽  
Fetal Loss ◽  
Endothelial Activation ◽  
Vascular Endothelial ◽  
Endothelial Surface ◽  
Endotoxin Contamination ◽  
Leukocyte Adhesion Molecules

Antiphospholipid antibodies (aPL) are associated with a syndrome of arterial and venous thrombosis and recurrent fetal loss. We have shown that IgG purified from patients with aPL activate vascular endothelial cells (EC), converting the steady-state, non-thrombotic endothelial surface to a pro-thrombotic state. The aPL-activated EC are characterized by the expression of leukocyte adhesion molecules, including ICAM-1, VCAM, and E-selectin. EC activation is dependent upon the presence of β2-GP-I, a cofactor necessary for anticardiolipin reactivity. In addition, EC activation is not attributable to endotoxin contamination, Fc receptor interactions, or immune complexes, but rather is the result of the specific anticardiolipin reactivity of the IgG. Endothelial activation by aPL may be an important mechanism by which these antibodies cause a hypercoagulable state.

20-Hydroxyeicosatetraenoic acid involved in endothelial activation and thrombosis

2015 ◽  
Vol 308 (11) ◽  
pp. H1359-H1367 ◽  
Author(s):  
Jiaxing Wang ◽  
Hua Li ◽  
Jinlong He ◽  
Bochuan Li ◽  
Qiankun Bao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Platelet Aggregation ◽  
Carotid Artery ◽  
Femoral Artery ◽  
Umbilical Vein ◽  
Endothelial Activation ◽  
Prolonged Treatment ◽  
Dependent Manner ◽  
Hydroxyeicosatetraenoic Acid

Endothelial cells play an important role in the process of coagulation and the function of platelets. We have previously reported that 20-hydroxyeicosatetraenoic acid (20-HETE), a metabolite of arachidonic acid, increased platelet aggregation and induced hemostasis. The purpose of the present study is to investigate whether 20-HETE-mediated endothelial activation has effect on the coagulation and platelet aggregation. C57Bl/6 mice were treated with PBS or 20-HETE (20 μg/kg) for 2 h, and then we performed a carotid artery or femoral artery thrombosis model by FeCl3. Detection of blood flow indicated that 20-HETE pretreatment accelerated formation of thrombus in both common carotid artery and femoral artery. In vitro, the secretion and expression of von Willebrand factor (vWF) in cultured human umbilical vein endothelial cells (HUVECs) with 20-HETE stimulation were increased, subsequently. The protein level of vWF in HUVECs was decreased at 1 h but increased with prolonged treatment with 20-HETE (>4 h). In contrast, vWF in the culture medium was increased under administration of 20-HETE at 1 h. As a result, adhesion of platelets on HUVECs was significantly increased by 20-HETE. In HUVECs, the extracellular signal-regulated kinase (ERK) pathway was activated by 20-HETE in a dose-dependent manner, and the inhibitors of ERK and L-type Ca2+channel blocked the release of vWF mediated by 20-HETE. In conclusion, 20-HETE instigates endothelial activation and induces the expression and secretion of vWF via the activation of ERK and calcium channel and therefore triggers thrombosis.

scholarly journals Ac-SDKP suppresses TNF-α-induced ICAM-1 expression in endothelial cells via inhibition of IκB kinase and NF-κB activation

2016 ◽  
Vol 310 (9) ◽  
pp. H1176-H1183 ◽  
Author(s):  
Liping Zhu ◽  
Xiao-Ping Yang ◽  
Branislava Janic ◽  
Nour-Eddine Rhaleb ◽  
Pamela Harding ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Leukocyte Adhesion ◽  
P38 Map Kinase ◽  
Dependent Manner ◽  
Human Coronary Artery ◽  
Mobility Shift ◽  
Autoimmune Myocarditis ◽  
Iκb Kinase ◽  
Subsequent Decrease ◽  
Tnf Α

N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a naturally occurring tetrapeptide that prevents inflammation and fibrosis in hypertension and other cardiovascular diseases. We previously showed that, in angiotensin II-induced hypertension, Ac-SDKP decreased the activation of nuclear transcription factor NF-κB, whereas, in experimental autoimmune myocarditis and hypertension animal models, it also reduced the expression of endothelial leukocyte adhesion molecule ICAM-1. However, the mechanisms by which Ac-SDKP downregulated ICAM-1 expression are still unclear. TNF-α is a proinflammatory cytokine that induces ICAM-1 expression in various cell types via TNF receptor 1 and activation of the classical NF-κB pathway. We hypothesized that in endothelial cells Ac-SDKP suppresses TNF-α-induced ICAM-1 expression by decreasing IKK phosphorylation that as a consequence leads to a decrease of IκB phosphorylation and NF-κB activation. To test this hypothesis, human coronary artery endothelial cells were treated with Ac-SDKP and then stimulated with TNF-α. We found that TNF-α-induced ICAM-1 expression was significantly decreased by Ac-SDKP in a dose-dependent manner. Ac-SDKP also decreased TNF-α-induced NF-κB translocation from cytosol to nucleus, as assessed by electrophoretic mobility shift assay, which correlated with a decrease in IκB phosphorylation. In addition, we found that Ac-SDKP decreased TNF-α-induced IKK phosphorylation and IKK-β expression. However, Ac-SDKP had no effect on TNF-α-induced phosphorylation of p38 MAP kinase or ERK. Thus we conclude that Ac-SDKP inhibition of TNF-α activation of canonical, i.e., IKK-β-dependent, NF-κB pathway and subsequent decrease in ICAM-1 expression is achieved via inhibition of IKK-β.

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