scholarly journals Effects of Lipopolysaccharide and Mannheimia haemolytica Leukotoxin on Bovine Lung Microvascular Endothelial Cells and Alveolar Epithelial Cells

2007 ◽  
Vol 15 (2) ◽  
pp. 338-347 ◽  
Author(s):  
David McClenahan ◽  
Katrina Hellenbrand ◽  
Dhammika Atapattu ◽  
Nicole Aulik ◽  
David Carlton ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Epithelial Cells ◽  
Morphological Changes ◽  
Cell Monolayer ◽  
Vascular Leakage ◽  
Mannheimia Haemolytica ◽  
Cell Monolayers ◽  
Activated Neutrophils ◽  
Microvascular Endothelial

ABSTRACT Bovine respiratory disease resulting from infection with Mannheimia haemolytica commonly results in extensive vascular leakage into the alveoli. M. haemolytica produces two substances, lipopolysaccharide (LPS) and leukotoxin (LKT), that are known to be important in inducing some of the pathological changes. In the present study, we examined bovine pulmonary epithelial (BPE) cell and bovine lung microvascular endothelial cell monolayer permeability, as measured by trans-well endothelial and epithelial cell electrical resistance (TEER), after incubation with LPS, LKT, or LPS-activated neutrophils. Endothelial cell monolayers exposed to LPS exhibited significant decreases in TEER that corresponded with increased levels of proinflammatory cytokines, apoptosis, and morphological changes. In contrast, BPE cells exposed to LPS increased the levels of production of inflammatory cytokines but displayed no changes in TEER, apoptosis, or visible morphological changes. Both cell types appeared to express relatively equal levels of the LPS ligand Toll-like receptor 4. However, TEER in BPE cell monolayers was decreased when the cells were incubated with LPS-activated neutrophils. Although the incubation of BPE cells with LKT decreased TEER, this was not reduced by the incubation of LKT with a neutralizing antibody and was reversed when LKT was preincubated with the LPS-neutralizing compound polymyxin B. Because BPE cells did not express the LKT receptor CD11a/CD18, we infer that contaminating LPS was responsible for the decreased TEER. In conclusion, LPS triggered changes in endothelial cells that would be consistent with vascular leakage, but neither LPS nor LKT caused similar changes in epithelial cells, unless neutrophils were also present.

THE BINDING OF ANTITHROMBIN TO CAPILLARY ENDOTHELIAL CELLS GROWN IN VITRO

1987 ◽  
Author(s):  
A de Agostini ◽  
J Marcum ◽  
R Rosenberg
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Heparan Sulfate ◽  
Cell Monolayer ◽  
Whole Cells ◽  
Cell Monolayers ◽  
Bacterial Enzyme ◽  
Capillary Endothelial Cells ◽  
Binding Cell

Cloned endothelial cells from rat epididymal fat pads synthesize anticoagulantly active heparan sulfate proteoglycans containing the disaccharide, GlcA→ AMN-3,6-O-SO3, which is a marker for the antithrombin-binding domain of heparin. To demonstrate that antithrombin (AT) binds to cell surface heparan sulfate, a binding assay employing 125I-AT and cell monolayers has been developed. Post-confluent endothelial cells (7 days) were incubated with radiolabeled AT for 1 h at 4° and washed with PBS. Bound radioactivity was quantitated after solubilizing whole cells. Under these conditions, ∼1% (2174±50 cpm/5x104 cells) of the 125I-AT bound to the endothelial cell monolayer, whereas none of the radiolabeled protein bound to CHO cells or bovine smooth muscle cells. Utilization of unlabeled AT (1 μM) in experiments conducted as described above resulted in a reduction (73%) of the binding of the labeled species to endothelial cells. To assess whether heparan sulfate was responsible for AT binding, cell monolayers were incubated for 1 h at 37° with purified Flavobacterium heparinase (0.2 units). Over 90% of 125I-AT binding to these cellular elements was suppressed with the bacterial enzyme. Internalization of radiolabeled AT by endothelial cells was examined by incubating the protease inhibitor and cells at 4° and 37 . An initial rapid binding was observed at both temperatures. At 4° AT binding plateaued within 15 min, whereas at 37° binding did not plateau until 60 min and was 30% greater than that observed at 4. These data suggest that surface-associated AT can be internalized by endothelial cells. In addition, AT binding was shown to increase with the length of endothelial cell postconfluence, indicating an accumulation of heparan sulfate by these cells during quiescence. In conclusion, our studies support the hypothesis that the vascular endothelium is coated with heparan sulfate-bound AT, which is responsible for the antithrombotic properties of these natural surfaces.

scholarly journals Pneumolysin Is the Main Inducer of Cytotoxicity to Brain Microvascular Endothelial Cells Caused by Streptococcus pneumoniae

2001 ◽  
Vol 69 (2) ◽  
pp. 845-852 ◽  
Author(s):  
Gregor Zysk ◽  
Barbara Katharina Schneider-Wald ◽  
Jae Hyuk Hwang ◽  
Levente Bejo ◽  
Kwang Sik Kim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Streptococcus Pneumoniae ◽  
Pneumococcal Meningitis ◽  
Primary Cultures ◽  
Cell Monolayer ◽  
Microvascular Endothelial Cells ◽  
Microvascular Endothelial Cell ◽  
Brain Microvascular Endothelial Cells ◽  
Microvascular Endothelial

ABSTRACT In pneumococcal meningitis it is assumed that bacteria cross the blood-brain barrier (BBB), which consists mainly of cerebral endothelial cells. The effect of Streptococcus pneumoniaeon the BBB was investigated with an in vitro BBB model using a human brain microvascular endothelial cell line (HBMEC) and primary cultures of bovine brain microvascular endothelial cells (BBMEC). Within a few hours of incubation with pneumococci, rounding and detachment of the HBMEC were observed, and the transendothelial electrical resistance of the BBMEC monolayer decreased markedly. An S. pneumoniaemutant deficient in pneumolysin did not affect the integrity of the endothelial cell monolayer. Neither cell wall fragments nor isolated pneumococcal cell walls induced changes of endothelial cell morphology. However, purified pneumolysin caused endothelial cell damage comparable to that caused by the viable pneumococci. The cell detachment was dependent on de novo protein synthesis and required the activities of caspase and tyrosine kinases. The results show that pneumolysin is an important component for damaging the BBB and may contribute to the entry of pneumococci into the cerebral compartment and to the development of brain edema in pneumococcal meningitis.

scholarly journals Rapid endothelial infection, endothelialitis and vascular damage characterise SARS-CoV-2 infection in a human lung-on-chip model

2020 ◽  
Author(s):  
Vivek V Thacker ◽  
Kunal Sharma ◽  
Neeraj Dhar ◽  
Gian-Filippo Mancini ◽  
Jessica Sordet-Dessimoz ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Epithelial Cells ◽  
Immune Cell ◽  
Morphological Changes ◽  
Vascular Damage ◽  
Alveolar Epithelial Cells ◽  
Barrier Integrity ◽  
On Chip ◽  
Cd31 Expression

AbstractSevere cases of COVID-19 present with hypercoagulopathies and systemic endothelialitis of the lung microvasculature. The dynamics of vascular damage, and whether it is a direct consequence of endothelial infection or an indirect consequence of immune cell mediated cytokine storms is unknown. This is in part because in vitro models are typically epithelial cell monocultures or fail to recapitulate vascular physiology. We use a vascularised lung-on-chip model where, consistent with monoculture reports, low numbers of SARS-CoV-2 virions are released apically from alveolar epithelial cells. However, rapid infection of the underlying endothelial layer leads to the generation of clusters of endothelial cells with low or no CD31 expression, a progressive loss of endothelial barrier integrity, and a pro-coagulatory microenvironment. These morphological changes do not occur if these cells are exposed to the virus apically. Viral RNA persists in individual cells, which generates a response that is skewed towards NF-KB mediated inflammation, is typified by IL-6 secretion even in the absence of immune cells, and is transient in epithelial cells but persistent in endothelial cells. Perfusion with Tocilizumab, an inhibitor of trans IL-6 signalling slows the loss of barrier integrity but does not prevent the formation of endothelial cell clusters with reduced CD31 expression. SARS-CoV-2 mediated endothelial cell damage occurs despite a lack of rapid viral replication, in a cell-type specific manner and independently of immune-cell mediated cytokine storms, whose effect would only exacerbate the damage.

Hemodynamic Shear Regulates Intercellular Forces and Permeability of Endothelial Cell Monolayers

2012 ◽  
Author(s):  
Lucas H. Ting ◽  
Nathan J. Sniadecki
Keyword(s):  
Endothelial Cells ◽  
Vascular Tissue ◽  
Morphological Changes ◽  
Cell Monolayer ◽  
Atherosclerotic Lesion ◽  
Shear Forces ◽  
Cell Monolayers ◽  
Smooth Flow ◽  
A Cell ◽  
Recirculation Zones

In the cardiovascular system, the flow of blood within the complex vascular network creates hemodynamic shear forces experienced by cells. Situated between the circulating blood and the bulk vascular tissue, the endothelium is a cell monolayer acting as a barrier that protects the underlying arterial tissue. Shear forces have been seen to interact with and regulate endothelial cells through mechanotransduction induced cytoskeletal changes within the cell [1]. Shear forces can be beneficial in cases of laminar flow, which are thought to be atheroprotective by aligning and organizing endothelial cells [2]. However, disturbances to a smooth flow field, caused by vessel bifurcations or obstructions like an implanted stent or a bulging atherosclerotic lesion, can cause recirculation zones to form downstream. In these flow regions, detrimental monolayer remodeling occurs which breaks down the endothelial barrier function [3]. Biochemically, it has been seen that shear forces drive signaling cascades in the Rho/Rac pathways that cascade into morphological changes in the cytoskeleton [4].

Inflammatory stress increases receptor for lysophosphatidylcholine in human microvascular endothelial cells

2003 ◽  
Vol 285 (4) ◽  
pp. H1786-H1789 ◽  
Author(s):  
Hazel Lum ◽  
Jing Qiao ◽  
Robert J. Walter ◽  
Fei Huang ◽  
Papasani V. Subbaiah ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
G Protein ◽  
Cell Monolayer ◽  
Microvascular Endothelial Cells ◽  
Pcr Analysis ◽  
Binding Studies ◽  
Tnf Α ◽  
Microvascular Endothelial ◽  
G Protein Coupled

The atherogenic serum lysophosphatidylcholine (LPC) is known to mediate vascular endothelial responses ranging from upregulation of adhesion molecules and growth factors to secretion of chemokines and superoxide anion. We investigated whether endothelial cells express receptors for LPC, which may account for their actions. Human brain microvascular (HBMEC) and dermal microvascular endothelial cells (HMEC) were prepared for RT-PCR analysis for possible expression of the G protein-coupled receptors, GPR4 and G2A, which are believed to be specific LPC receptors. Results indicated that HBMEC expressed low basal GPR4 mRNA, but stimulation with tumor necrosis factor-α (TNF-α) (100 U/ml) or H2O2 (50 μmol/l) for 2 h or overnight upregulated expression severalfold. In contrast, HMEC expressed high basal GPR4 mRNA, which was not further increased by either TNF-α or H2O2 stimulation. Another LPC receptor, G2A, was not detected in either endothelial cell type. Competition binding studies were made to evaluate specific binding of [3H]LPC to the intact endothelial cell monolayer. Basal specific [3H]LPC binding in HBMEC was approximately eight times lower than in HMEC; however, TNF-α or H2O2 stimulation increased [3H]LPC binding on HMBEC but not HMEC. The results indicated that GPR4 expression was consistent with specific [3H]LPC binding. Overall, we report that endothelial cells selectively expressed GPR4, a specific LPC receptor. Furthermore, GPR4 expression by HBMEC, but not HMEC, was increased by inflammatory stresses. We conclude that endogenous GPR4 in endothelial cells may be a potential G protein-coupled receptor by which LPC signals proinflammatory activities.

scholarly journals Cytoplasmic dye transfer between metastatic tumor cells and vascular endothelium.

1991 ◽  
Vol 115 (5) ◽  
pp. 1375-1382 ◽  
Author(s):  
M E el-Sabban ◽  
B U Pauli
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Critical Role ◽  
Cell Monolayer ◽  
Mammary Adenocarcinoma ◽  
Dye Transfer ◽  
Cell Monolayers ◽  
Adenocarcinoma Cells

Metastatic colonization of a secondary organ site is initiated by the attachment of blood-borne tumor cells to organ-specific adhesion molecules expressed on the surface of microvascular endothelial cells. Using digital video imaging microscopy and fluorescence activated cell sorting techniques, we show here that highly metastatic cells (B16-F10 murine melanoma and R3230AC-MET rat mammary adenocarcinoma cells) previously labeled with the fluorescent dye BCECF begin to transfer dye to endothelial cell monolayers shortly after adhesion is established. The extent of BCECF transfer to endothelial cell monolayers is dependent upon the number of BCECF-labeled tumor cells seeded onto the endothelial cell monolayer and the time of coculture of the two cell types, as visualized by an increase in the number of BCECF-positive cells among cells stained with an endothelial cell-specific mAb. Dye transfer to BAEC monolayers proceeds with a progressive loss of fluorescence intensity in the BCECF-labeled tumor cell population with time of coculture. The transfer of dye is bidirectional and sensitive to inhibition by 1-heptanol. In contrast, poorly metastatic B16-F0 melanoma cells and non-metastatic R3230AC-LR mammary adenocarcinoma cells do not efficiently couple with vascular endothelial cells. It is inferred from these experiments and from the amounts of connexin43 mRNA expressed by tumor cells that tumor cell/endothelial cell communication is mediated by gap junctional channels and that this interaction may play a critical role in tumor cell extravasation at secondary sites.

Arthrospira platensis accelerates the formation of an endothelial cell monolayer and protects against endothelial cell detachment after bacterial contamination

2021 ◽  
pp. 1-11
Author(s):  
A. Krüger-Genge ◽  
S. Steinbrecht ◽  
C.G.H. Jung ◽  
Sophia Westphal ◽  
Stefanie Klöpzig ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Bacterial Contamination ◽  
Cell Monolayer ◽  
Arthrospira Platensis ◽  
Bacterial Toxin ◽  
Cell Detachment ◽  
Endothelial Cell Monolayer ◽  
Positive Effects ◽  
Anti Oxidant

Within the last years a comprehensive number of scientific studies demonstrated beneficial effect of Arthropira platensis (AP) as dietary supplement due to a high content of proteins, minerals and vitamins. Positive effects like promoting the immune system, reducing inflammation and an anti-oxidant capacity are reported. In this study, the effect of an aqueous AP extract on primary human venous endothelial cells (HUVEC) was investigated. In addition, the effect of AP on HUVEC treated with a bacterial toxin (lipopolysaccharide, LPA), inducing an activation of HUVEC and cellular detachment, was analyzed. Depending on the concentration of AP extract a significantly accelerated formation of an endothelial cell monolayer was observed. Furthermore, the detachment of HUVEC after LPA addition was dramatically reduced by AP. In conclusion, the data are promising and indicatory for an application of Arthrospira platensis in the clinical field.

A Porcine Model for Adipose Tissue-Derived Endothelial Cell Transplantation

1992 ◽  
Vol 1 (4) ◽  
pp. 293-298 ◽  
Author(s):  
Carlton Young ◽  
Bruce E. Jarrell ◽  
James B. Hoying ◽  
Stuart K. Williams
Keyword(s):  
Endothelial Cells ◽  
Adipose Tissue ◽  
Endothelial Cell ◽  
Cell Transplantation ◽  
Animal Studies ◽  
Porcine Model ◽  
Cell Isolation ◽  
Microvascular Endothelial Cell ◽  
Microvascular Endothelium ◽  
Microvascular Endothelial

The transplantation of endothelial cells represents a technology which has been suggested for applications ranging from improvement in function of implanted vascular devices to genetic therapy. The use of microvascular endothelial cell transplantation has seen increased use both in animal studies as well as clinical use. This report describes our techniques for the isolation and establishment of initial cultures of microvascular endothelial cells derived from porcine fat. A variety of anatomic sites within the pig were evaluated to determine the appropriateness of different sources of fat for endothelial cell isolation. The properitoneal fat was determined to be optimal due to the predominance of endothelium in this tissue and the ease of isolation of microvascular endothelium following collagenase digestion. The study of endothelial cell transplantation in the porcine model is now possible using the methods described for adipose tissue-derived micro vessel endothelial cell isolation.

Isolation and characterization of human and rat cardiac microvascular endothelial cells

1993 ◽  
Vol 264 (2) ◽  
pp. H639-H652 ◽  
Author(s):  
M. Nishida ◽  
W. W. Carley ◽  
M. E. Gerritsen ◽  
O. Ellingsen ◽  
R. A. Kelly ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Microvascular Endothelial Cells ◽  
Microvascular Endothelium ◽  
Adult Rat ◽  
Isolation And Characterization ◽  
Ventricular Tissue ◽  
Microvascular Endothelial ◽  
Cardiac Microvascular Endothelial Cells

Although reciprocal intercellular signaling may occur between endocardial or microvascular endothelium and cardiac myocytes, suitable in vitro models have not been well characterized. In this report, we describe the isolation and primary culture of cardiac microvascular endothelial cells (CMEC) from both adult rat and human ventricular tissue. Differential uptake of fluorescently labeled acetylated low-density lipoprotein (Ac-LDL) indicated that primary isolates of rat CMEC were quite homogeneous, unlike primary isolates of human ventricular tissue, which required cell sorting based on Ac-LDL uptake to create endothelial cell-enriched primary cultures. The endothelial phenotype of both primary isolates and postsort subcultured CMEC and their microvascular origin were determined by characteristic histochemical staining for a number of endothelial cell-specific markers, by the absence of cells with fibroblast or pericyte-specific cell surface antigens, and by rapid tube formation on purified basement membrane preparations. Importantly, [3H]-thymidine uptake was increased 2.3-fold in subconfluent rat microvascular endothelial cells 3 days after coculture with adult rat ventricular myocytes because of release of an endothelial cell mitogen(s) into the extracellular matrix, resulting in a 68% increase in cell number compared with CMEC in monoculture. Thus biologically relevant cell-to-cell interactions can be modeled with this in vitro system.

Sign in / Sign up

Export Citation Format

Share Document