scholarly journals Autoantibodies from Patients with Scleroderma Renal Crisis Promote PAR-1 Receptor Activation and IL-6 Production in Endothelial Cells

2021 ◽  
Vol 22 (21) ◽  
pp. 11793
Author(s):  
Michèle Simon ◽  
Christian Lücht ◽  
Isa Hosp ◽  
Hongfan Zhao ◽  
Dashan Wu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vascular Endothelial Cells ◽  
Receptor Activation ◽  
Scleroderma Renal Crisis ◽  
Mobility Shift ◽  
Western Blots ◽  
Life Threatening ◽  
Electrophoretic Mobility Shift Assays ◽  
Renal Crisis

Background. Scleroderma renal crisis (SRC) is a life-threatening complication of systemic sclerosis (SSc). Autoantibodies (Abs) against endothelial cell antigens have been implicated in SSc and SRC. However, their detailed roles remain poorly defined. Pro-inflammatory cytokine interleukin-6 (IL-6) has been found to be increased in SSc, but its role in SRC is unclear. Here, we aimed to determine how the autoantibodies from patients with SSc and SRC affect IL-6 secretion by micro-vascular endothelial cells (HMECs). Methods. Serum IgG fractions were isolated from either SSc patients with SRC (n = 4) or healthy individuals (n = 4) and then each experiment with HMECs was performed with SSc-IgG from a separate patient or separate healthy control. IL-6 expression and release by HMECs was assessed by quantitative reverse transcription and quantitative PCR (RT-qPCR) and immunoassays, respectively. The mechanisms underlying the production of IL-6 were analyzed by transient HMEC transfections with IL-6 promoter constructs, electrophoretic mobility shift assays, Western blots and flow cytometry. Results. Exposure of HMECs to IgG from SSc patients, but not from healthy controls, resulted in a time- and dose-dependent increase in IL-6 secretion, which was associated with increased AKT, p70S6K, and ERK1/2 signalling, as well as increased c-FOS/AP-1 transcriptional activity. All these effects could be reduced by the blockade of the endothelial PAR-1 receptor and/or c-FOS/AP-1silencing. Conclusions. Autoantibodies against PAR-1 found in patients with SSc and SRC induce IL-6 production by endothelial cells through signalling pathways controlled by the AP-1 transcription factor. These observations offer a greater understanding of adverse endothelial cell responses to autoantibodies present in patients with SRC.

scholarly journals Rhizopus oryzae Adheres to, Is Phagocytosed by, and Damages Endothelial Cells In Vitro

2005 ◽  
Vol 73 (2) ◽  
pp. 778-783 ◽  
Author(s):  
Ashraf S. Ibrahim ◽  
Brad Spellberg ◽  
Valentina Avanessian ◽  
Yue Fu ◽  
John E. Edwards
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Rhizopus Oryzae ◽  
Vascular Endothelial Cells ◽  
Cell Damage ◽  
Umbilical Vein ◽  
Tissue Necrosis ◽  
Life Threatening ◽  
Umbilical Vein Endothelial Cells

ABSTRACT Rhizopus oryzae is the most common cause of zygomycosis, a life-threatening infection that usually occurs in immunocompromised patients. A characteristic hallmark of zygomycosis is angioinvasion by the fungus, resulting in thrombosis and subsequent tissue necrosis. Interactions between R. oryzae and vascular endothelial cells are therefore likely of central importance to the organism's pathogenetic strategy. We studied the ability of R. oryzae to adhere to and damage human umbilical vein endothelial cells (HUVECs) in vitro. We report that R. oryzae spores and germ tubes adhere to HUVECs, whereas only spores adhere to subendothelial matrix proteins. Additionally, R. oryzae damages endothelial cells. This endothelial cell damage requires direct contact and subsequent phagocytosis of the fungus. Surprisingly, R. oryzae viability was not required for damage, but phagocytosis was required for dead R. oryzae to cause damage. These results elucidate the nature of R. oryzae-endothelial cell interactions, which are likely central to the angioinvasion and tissue necrosis seen during zygomycotic infections. The fact that dead R. oryzae damage human endothelial cells may, in part, explain the lack of efficacy of fungicidal agents during clinical disease.

The Endothelial Cell and the Factor VIII Bypassing Activity of Prothrombin Complex Concentrate

1988 ◽  
Vol 60 (02) ◽  
pp. 226-229 ◽  
Author(s):  
Jerome M Teitel ◽  
Hong-Yu Ni ◽  
John J Freedman ◽  
M Bernadette Garvey
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Factor Viii ◽  
Prothrombin Complex Concentrate ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial ◽  
Monolayer Cultures ◽  
Coagulant Activity ◽  
Time Courses ◽  
Privileged Site

SummarySome classical hemophiliacs have a paradoxical hemostatic response to prothrombin complex concentrate (PCC). We hypothesized that vascular endothelial cells (EC) may contribute to this “factor VIII bypassing activity”. When PCC were incubated with suspensions or monolayer cultures of EC, they acquired the ability to partially bypass the defect of factor VIII deficient plasma. This factor VIII bypassing activity distributed with EC and not with the supernatant PCC, and was not a general property of intravascular cells. The effect of PCC was even more dramatic on fixed EC monolayers, which became procoagulant after incubation with PCC. The time courses of association and dissociation of the PCC-derived factor VIII bypassing activity of fixed and viable EC monolayers were both rapid. We conclude that EC may provide a privileged site for sequestration of constituents of PCC which express coagulant activity and which bypass the abnormality of factor VIII deficient plasma.

Alterations in Vascular Endothelial Cell-related Plasma Proteins In Thalassaemic Patients and their Correlation with Clinical Symptoms

1995 ◽  
Vol 74 (04) ◽  
pp. 1045-1049 ◽  
Author(s):  
P Butthep ◽  
A Bunyaratvej ◽  
Y Funahara ◽  
H Kitaguchi ◽  
S Fucharoen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Immunosorbent Assay ◽  
Plasma Proteins ◽  
Clinical Symptoms ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial Cell ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vascular Endothelial ◽  
Leg Ulcers

SummaryAn increased level of plasma thrombomodulin (TM) in α- and β- thalassaemia was demonstrated using an enzyme-linked immunosorbent assay (ELISA). Nonsplenectomized patients with β-thalassaemia/ haemoglobin E (BE) had higher levels of TM than splenectomized cases (BE-S). Patients with leg ulcers (BE-LU) were found to have the highest increase in TM level. Appearance of larger platelets in all types of thalassaemic blood was observed indicating an increase in the number of younger platelets. These data indicate that injury of vascular endothelial cells is present in thalassaemic patients.

scholarly journals An autoantibody directed against human thrombin anion-binding exosite in a patient with arterial thrombosis: effects on platelets, endothelial cells, and protein C activation

Blood ◽  
1994 ◽  
Vol 84 (6) ◽  
pp. 1843-1850 ◽  
Author(s):  
E Arnaud ◽  
M Lafay ◽  
P Gaussem ◽  
V Picard ◽  
M Jandrot-Perrus ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Arterial Thrombosis ◽  
Protein C ◽  
Receptor Activation ◽  
Anion Binding ◽  
Thrombin Receptor ◽  
Cell Functions ◽  
Human Thrombin

Abstract An autoantibody, developed by a patient with severe and recurrent arterial thrombosis, was characterized to be directed against the anion- binding exosite of thrombin, and inhibited all thrombin interactions requiring this secondary binding site without interfering with the catalytic site. The effect of the antibody was studied on thrombin interactions with platelets and endothelial cells from human umbilical veins (HUVEC). The autoantibody specifically and concentration- dependently inhibited alpha-thrombin-induced platelet activation and prostacyclin (PGI2) synthesis from HUVEC. It had no effect when gamma- thrombin or the thrombin receptor activation peptide SFLLR were the inducers. The effect of the antibody on protein C activation has been studied. The antibody blocked the thrombin-thrombomodulin activation of protein C. The inhibition of the activation was maximal with a low concentration of thrombomodulin. The fact that the autoantibody inhibited concentration-dependent alpha-thrombin-induced platelet and endothelial cell functions emphasizes the crucial role of the anion- binding exosite of thrombin to activate its receptor. In regard to the pathology, the antibody inhibited two vascular processes implicated in thrombin-antithrombotic functions, PGI2 secretion, and protein C activation, which could be implicated in this arterial thrombotic disease.

Inhibition of inwardly rectifying K+ channels by cGMP in pulmonary vascular endothelial cells

2002 ◽  
Vol 283 (2) ◽  
pp. L297-L304 ◽  
Author(s):  
Larissa A. Shimoda ◽  
Laura E. Welsh ◽  
David B. Pearse
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vascular Endothelial Cells ◽  
Cell Types ◽  
Protective Mechanism ◽  
Cell Integrity ◽  
Barrier Dysfunction ◽  
Whole Cell Patch Clamp ◽  
Inward Currents ◽  
Inwardly Rectifying

Endothelial barrier dysfunction is typically triggered by increased intracellular Ca2+concentration. Membrane-permeable analogs of guanosine 3′,5′-cyclic monophosphate (cGMP) prevent disruption of endothelial cell integrity. Because membrane potential ( E m), which influences the electrochemical gradient for Ca2+ influx, is regulated by K+ channels, we investigated the effect of 8-bromo-cGMP on E m and inwardly rectifying K+ (KIR) currents in bovine pulmonary artery and microvascular endothelial cells (BPAEC and BMVEC), using whole cell patch-clamp techniques. Both cell types exhibited inward currents at potentials negative to −50 mV that were abolished by application of 10 μM Ba2+, consistent with KIR current. Ba2+ also depolarized both cell types. 8-Bromo-cGMP (10−3 M) depolarized BPAEC and BMVEC and inhibited KIR current. Pretreatment with Rp-8-cPCT-cGMPS or KT-5823, protein kinase G (PKG) antagonists, did not prevent current inhibition by 8-bromo-cGMP. These data suggest that 8-bromo-cGMP induces depolarization in BPAEC and BMVEC due, in part, to PKG-independent inhibition of KIR current. The depolarization could be a protective mechanism that prevents endothelial cell barrier dysfunction by reducing the driving force for Ca2+ entry.

Abstract P217: Mitochondrial N-Formyl Peptides Elicit Changes in Endothelial Cell Cytoskeleton via Formyl Peptide Receptor Activation

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Camilla F Wenceslau ◽  
Cameron G McCarthy ◽  
R.Clinton Webb
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vascular Dysfunction ◽  
Receptor Activation ◽  
Vascular Leakage ◽  
Formyl Peptide Receptor ◽  
Experimental Hypertension ◽  
Peptide Receptor ◽  
Formyl Peptide ◽  
Formyl Peptides

One major pathophysiological characteristic of cardiovascular disease, including hypertension, is vascular dysfunction. Recently, we demonstrated that mitochondrial damage-associated molecular patterns are elevated in the circulation of SHR. Mitochondria carry hallmarks of their bacterial ancestry and one of these hallmarks is that this organelle still uses an N-formyl-methionyl-tRNA as an initiator of protein synthesis. We observed that mitochondrial N-formyl peptides (F-MIT) infusion into rats induces inflammation and vascular dysfunction, including vascular leakage, via formyl peptide receptor (FPR) activation. However, neutrophil depletion did not change this response. Therefore, we hypothesize that F-MIT via FPR activation elicits changes directly to cytoskeleton-regulating proteins in vascular cells, which may lead to increased vascular permeability. To test this hypothesis we used vascular smooth muscle cells (VSMC) and endothelial cells harvested from aortas of Sprague-Dawley rats (n=5) and human donors (n=5), respectively. Cells were divided into three groups for Western blot analysis of cytoskeleton-regulating proteins. The cells were incubated for 20 minutes in medium with either vehicle (non-formylated peptide), F-MIT (10 μM), or F-MIT after a 5-minute pre-incubation with FPR1 and 2 antagonists (Cyclosporine H, CsH, 1 μM and WRW4, 10 μM). In endothelial cells, the treatment with F-MIT increased the protein expression of RhoA/ROCK (Rho: 1.8 fold vs. Veh; ROCK: 1.4 fold vs. Veh, p<0.05), cell division control protein 42 (CDC42) (2.0 fold vs. Veh, p<0.05) and phospho-myosin light chain (MLC) Thr/Ser19 (1.5 fold vs. Veh, p<0.05). These changes were all abolished in the presence of FPR antagonists. On the other hand, F-MIT decreased expression of phospho-MLC (0.6 fold vs. Veh, p<0.05) and CDC42 (0.5 fold vs. Veh, p<0.05) and did not change RhoA/ROCK expression in VSMC. In conclusion, F-MIT, via FPR activation, elicits direct changes in endothelial cell and VSMC cytoskeleton-regulating proteins. This interaction can lead to endothelial contraction, increased vascular leakage and attenuated barrier function as observed in clinical and experimental hypertension.

scholarly journals Human vascular adhesion protein 1 (VAP-1) is a unique sialoglycoprotein that mediates carbohydrate-dependent binding of lymphocytes to endothelial cells.

1996 ◽  
Vol 183 (2) ◽  
pp. 569-579 ◽  
Author(s):  
M Salmi ◽  
S Jalkanen
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vascular Endothelial Cells ◽  
Lymphoid Tissues ◽  
Vascular Endothelial ◽  
Adhesion Protein ◽  
Culture Model ◽  
Vascular Adhesion ◽  
Vascular Adhesion Protein 1

The regulated interactions of leukocytes with vascular endothelial cells are crucial in controlling leukocyte traffic between blood and tissues. Vascular adhesion protein-1 (VAP-1) is a novel, human endothelial cell molecule that mediates tissue-selective lymphocyte binding. Two species (90 and 170 kD) of VAP-1 exist in lymphoid tissues. Glycosidase digestions revealed that the mature 170-kD form of VAP-1 expressed on the lumenal surfaces of vessels is a heavily sialylated glycoprotein. The sialic acids are indispensable for the function of VAP-1, since the desialylated form of VAP-1 no longer mediates lymphocyte binding. We also show that L-selectin is not required for binding of activated lymphocytes to VAP-1 under conditions of shear stress. The 90-kD form of VAP-1 was only seen in an organ culture model, and may represent a monomeric or proteolytic form of the larger species. These data indicate that L-selectin negative lymphocytes can bind to tonsillar venules via the VAP- 1-mediated pathway. Moreover, our findings extend the role of carbohydrate-mediated binding in lymphocyte-endothelial cell interactions beyond the known selectins. In conclusion, VAP-1 naturally exists as a 170-kD sialoglycoprotein that uses sialic acid residues to interact with its counter-receptors on lymphocytes under nonstatic conditions.

Effects of Fluid Shear Stress on Endothelial Cell Invasion Into Three-Dimensional Matrices

2007 ◽  
Author(s):  
Hojin Kang ◽  
Kayla J. Bayless ◽  
Roland Kaunas
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Endothelial Cell ◽  
Cell Invasion ◽  
Fluid Shear Stress ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Shear Stresses ◽  
Collagen Gels ◽  
Fluid Shear

We have previously developed a cell culture model to study the effects of angiogenic factors, such as sphingosine-1-phosphate (S1P), on the invasion of endothelial cells into the underlying extracellular matrix. In addition to biochemical stimuli, vascular endothelial cells are subjected to fluid shear stress due to blood flow. The present study is aimed at determining the effects of fluid shear stress on endothelial cell invasion into collagen gels. A device was constructed to apply well-defined fluid shear stresses to confluent human umbilical vein endothelial cells (HUVECs) seeded on collagen gels. Fluid shear stress induced significant increases in cell invasion with a maximal induction at ∼5 dyn/cm2. These results provide evidence that fluid shear stress is a significant stimulus for endothelial cell invasion and may play a role in regulating angiogenesis.

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