GPI-linked endothelial CD14 contributes to the detection of LPS

2006 ◽  
Vol 291 (1) ◽  
pp. H473-H481 ◽  
Author(s):  
Katie L. Lloyd ◽  
Paul Kubes
Keyword(s):  
Endothelial Cells ◽  
Plasma Proteins ◽  
Umbilical Vein ◽  
Leukocyte Recruitment ◽  
Endothelial Surface ◽  
Binding Epitope ◽  
Endothelial Response ◽  
Low Levels ◽  
Umbilical Vein Endothelial Cells ◽  
Phosphatidylinositol Phospholipase C

The inflammatory endothelial response to LPS is critical to the host's surviving a gram-negative bacterial infection. In this study we investigated whether human endothelial cells express the functional coreceptor for LPS, CD14, and most importantly whether it is glycosylphosphatidylinositol (GPI) linked. We also examined whether plasma proteins could reconstitute an LPS response in CD14-inhibited endothelium. RT-PCR- and CD14-specific MAbs demonstrated CD14 expression on primary human umbilical vein endothelial cells (HUVEC) but not passaged HUVEC. The amino acid sequence of endothelial CD14 was 99% homologous to CD14 on monocytes. Endothelium responded to relatively low levels of LPS in the absence of plasma, and this was entirely dependent on CD14. Removal of GPI-linked proteins with phosphatidylinositol-phospholipase C prevented LPS detection and subsequent protein synthesis (E-selectin expression). Endothelial CD14 was sufficient to initiate functional leukocyte recruitment, an event inhibited by blocking its LPS binding epitope and also by removing CD14 from the endothelial surface. Plasma proteins restored only ∼30% of the LPS response in CD14-inhibited endothelium. In conclusion, our results strongly support an important role for endothelial membrane CD14 in the activation of endothelium for leukocyte recruitment.

scholarly journals Flagellar Hook Protein FlgE Induces Microvascular Hyperpermeability via Ectopic ATP Synthase β on Endothelial Surface

2021 ◽  
Vol 11 ◽  
Author(s):  
Yuanyuan Li ◽  
Ying Shen ◽  
Yudan Zheng ◽  
Shundong Ji ◽  
Mengru Wang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Abdominal Cavity ◽  
Tube Formation ◽  
Atp Production ◽  
Endothelial Surface ◽  
Umbilical Vein Endothelial Cells

We previously demonstrated the immunostimulatory efficacy of Pseudomonas aeruginosa flagellar hook protein FlgE on epithelial cells, presumably via ectopic ATP synthases or subunits ATP5B on cell membranes. Here, by using recombinant wild-type FlgE, mutant FlgE (FlgEM; bearing mutations on two postulated critical epitopes B and F), and a FlgE analog in pull-down assay, Western blotting, flow cytometry, and ELISA, actual bindings of FlgE proteins or epitope B/F peptides with ATP5B were all confirmed. Upon treatment with FlgE proteins, human umbilical vein endothelial cells (HUVECs) and SV40-immortalized murine vascular endothelial cells manifested decreased proliferation, migration, tube formation, and surface ATP production and increased apoptosis. FlgE proteins increased the permeability of HUVEC monolayers to soluble large molecules like dextran as well as to neutrophils. Immunofluorescence showed that FlgE induced clustering and conjugation of F-actin in HUVECs. In Balb/c-nude mice bearing transplanted solid tumors, FlgE proteins induced a microvascular hyperpermeability in pinna, lungs, tumor mass, and abdominal cavity. All effects observed in FlgE proteins were partially or completely impaired in FlgEM proteins or blocked by pretreatment with anti-ATP5B antibodies. Upon coculture of bacteria with HUVECs, FlgE was detectable in the membrane and cytosol of HUVECs. It was concluded that FlgE posed a pathogenic ligand of ectopic ATP5B that, upon FlgE–ATP5B coupling on endothelial cells, modulated properties and increased permeability of endothelial layers both in vitro and in vivo. The FlgE-ectopic ATP5B duo might contribute to the pathogenesis of disorders associated with bacterial infection or ectopic ATP5B-positive cells.

Adhesion of flowing neutrophils to cultured endothelial cells after hypoxia and reoxygenation in vitro

1995 ◽  
Vol 269 (4) ◽  
pp. H1398-H1406 ◽  
Author(s):  
G. E. Rainger ◽  
A. Fisher ◽  
C. Shearman ◽  
G. B. Nash
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Platelet Activating Factor ◽  
Neutrophil Recruitment ◽  
Severe Hypoxia ◽  
Adhesion Assay ◽  
Endothelial Response ◽  
And Migration ◽  
Umbilical Vein Endothelial Cells

Using a novel in-line deoxygenating system linked to an in vitro flow-based adhesion assay and video microscopy, we have studied neutrophil recruitment and migration after hypoxia and reoxygenation of cultured human umbilical vein endothelial cells (HUVEC). Unstimulated purified neutrophils were perfused over reoxygenating HUVEC immediately after various periods of endothelial hypoxia. Adhesion to HUVEC was dependent on the duration of hypoxia, with 30, 60, and 100 min of exposure causing graded increments in neutrophil recruitment. The degree of hypoxia also markedly influenced the endothelial response. Severe hypoxia (O2 < 2.5%) induced stationary attachment and then migration of neutrophils, in contrast to rolling adhesion alone under a less intense regime (O2 = 2.5-4.0%). Judged from studies with monoclonal antibodies, P-selectin was essential for adhesion after severe hypoxia, and neutrophil immobilization was attributable to the activation of neutrophil beta 2-integrin. Perfusion of neutrophils with an antibody against interleukin-8 or a platelet-activating factor antagonist reduced levels of adhesion. However, IL-8 appeared to be the dominant agent involved in the immobilization from flow, whereas platelet-activating factor was the more potent agent involved in initiating subendothelial migration. Thus endothelial cells alone can initiate all stages of adhesion and migration of flowing neutrophils after hypoxia and reperfusion.

Tissue factor and tissue factor pathway inhibitor levels in trophoblast cells: implications for placental hemostasis

2004 ◽  
Vol 92 (10) ◽  
pp. 776-786 ◽  
Author(s):  
Benjamin Brenner ◽  
Tamar Katz ◽  
Yohei Miyagi ◽  
Naomi Lanir ◽  
Anat Aharon
Keyword(s):  
Endothelial Cells ◽  
Tissue Factor ◽  
Tissue Factor Pathway Inhibitor ◽  
Umbilical Vein ◽  
Maternal Blood ◽  
Placental Function ◽  
Protein Levels ◽  
Tissue Factor Pathway ◽  
Low Levels ◽  
Umbilical Vein Endothelial Cells

SummaryThe placenta is a highly vascularized organ with fetal and maternal blood supply. Syncytiotrophoblasts (STB), which line the placenta villous are possibly involved in local hemostatic mechanisms.The aim of this study was to evaluate the levels of tissue factor (TF) and its inhibitors, tissue factor pathway inhibitor (TFPI,TFPI-2), in STB model within hemostatic and inflammatory environments. Human primary STB cell cultures were characterized by vascular and hormonal markers. TF and TFPI mRNA expression, protein levels and activity were determined and compared to human umbilical vein endothelial cells (HUVEC). High levels of TF were demonstrated in STB cells compared to low levels in HUVEC. In contrast, STB expressed lower TFPI levels than HUVEC. LPS and TNFα increased the high constitutive TF in STB, whereas LPS and IL-1α further reduced TFPI levels. The procoagulant tendency of STB identified by us may reflect the physiological need for immediate inhibition of hemorrhage in the placental inter-villous spaces in basal and inflammatory conditions.This hemostatic balance may be critical for normal placental function and pregnancy outcome.

Single-Chain and Two-Chain Tissue-Type Plasminogen Activator (t-PA) Bind Differently to Cultured Human Endothelial Cells

1989 ◽  
Vol 62 (02) ◽  
pp. 699-703 ◽  
Author(s):  
Rob J Aerts ◽  
Karin Gillis ◽  
Hans Pannekoek
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Binding Sites ◽  
Umbilical Vein ◽  
Tissue Type ◽  
Single Chain ◽  
Human Endothelial Cells ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Umbilical Vein Endothelial Cells

SummaryIt has recently been shown that the fibrinolytic components plasminogen and tissue-type plasminogen activator (t-PA) both bind to cultured human umbilical vein endothelial cells (HUVEC). After cleavage of t-PA by plasmin, “single-chain” t-PA (sct-PA) is converted into “two-chain” t-PA (tct-PA), which differs from the former in a number of respects. We compared binding of sct-PA and tct-PA to the surface of HUVEC. Removal of t-PA bound to HUVEC by a mild treatment with acid and a subsequent quantification of eluted t-PA both by activity- and immunoradiometric assays revealed that, at concentrations between 10 and 500 nM, HUVEC bind about 3-4 times more sct-PA than tct-PA. At these concentrations, both sct-PA and tct-PA remain active when bound to HUVEC. Mutual competition experiments showed that sct-PA and tct-PA can virtually fully inhibit binding of each other to HUVEC, but that an about twofold higher concentration of tct-PA is required to prevent halfmaximal binding of sct-PA than visa versa. These results demonstrate that sct-PA and tct-PA bind with different affinities to the same binding sites on HUVEC.

Studies of the Factor Xa-Dependent Inhibitor of Factor VIIa/Tissue Factor (Extrinsic Pathway Inhibitor) from Cell Supernates of Cultured Human Umbilical Vein Endothelial Cells

1989 ◽  
Vol 61 (01) ◽  
pp. 101-105 ◽  
Author(s):  
Bonnie J Warn-Cramer ◽  
Fanny E Almus ◽  
Samuel I Rapaport
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
Tissue Factor ◽  
Phorbol Ester ◽  
Umbilical Vein ◽  
Primary Cultures ◽  
Factor Xa ◽  
Extrinsic Pathway ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

SummaryCultured human umbilical vein endothelial cells (HUVEC) have been reported to produce extrinsic pathway inhibitor (EPI), the factor Xa-dependent inhibitor of factor VHa/tissue factor (TF). We examined the release of this inhibitor from HUVEC as a function of their growth state and in response to the induction of endothelial cell TF activity. HUVEC constitutively produced significant amounts of EPI at all stages of their growth in culture including the post-confluent state. Rate of release varied over a 3-fold range for primary cultures from 12 different batches of pooled umbilical cord cells. Constitutive EPI release was unaltered during a 6 hour period of induction of TF activity with thrombin or phorbol ester but slowed during longer incubation of the cells with phorbol ester. Whereas plasma contains two molecular weight forms of EPI, only the higher of these two molecular weight forms was demonstrable by Western analysis of HUVEC supernatants with 125I-factor Xa as the ligand.

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