scholarly journals Neutrophil migration across monolayers of cytokine-prestimulated endothelial cells: a role for platelet-activating factor and IL-8.

1992 ◽  
Vol 117 (3) ◽  
pp. 565-572 ◽  
Author(s):  
T W Kuijpers ◽  
B C Hakkert ◽  
M H Hart ◽  
D Roos
Keyword(s):  
Endothelial Cells ◽  
Neutrophil Migration ◽  
Platelet Activating Factor ◽  
Human Neutrophils ◽  
Neutrophil Adherence ◽  
Paf Receptor ◽  
And Migration ◽  
Web 2086 ◽  
Paf Receptor Antagonist

In a previous study we observed that neutrophils respond with a rapid rise in [Ca2+]i during adherence to cytokine-activated endothelial cells (EC), caused by EC membrane-associated platelet-activating factor (PAF). In the present study, we investigated whether this form of PAF was important in neutrophil adherence and migration across monolayers of rIL-1 beta- or rTNF alpha-prestimulated EC. PAF receptor antagonists prevented neutrophil migration across cytokine-pretreated EC by approximately 60% (P less than 0.005) without interfering with the process of adherence. The antagonists WEB 2086 and L-652,731 had no effect on neutrophil migration across resting EC induced by formylmethionyl-leucyl-phenylalanine (FMLP). A murine anti-IL-8 antiserum was found to also partially inhibit the neutrophil transmigration across cytokine-activated EC. When the anti-IL-8 antiserum was used in combination with a PAF receptor antagonist, neutrophil migration across cytokine-pretreated monolayers of EC was completely prevented. During transmigration, LAM-1 and CD44 on the neutrophils were down-modulated; both WEB 2086 and anti-IL-8 antiserum partially prevented this down-modulation caused by cytokine-prestimulated EC. Our results indicate that human neutrophils are activated and guided by EC-associated PAF and EC-derived IL-8 during the in vitro diapedesis in between cytokine-stimulated EC.

Exogenous xanthine promotes neutrophil adherence to cultured endothelial cells

1997 ◽  
Vol 273 (2) ◽  
pp. G342-G347
Author(s):  
H. Ichikawa ◽  
R. E. Wolf ◽  
T. Y. Aw ◽  
N. Ohno ◽  
L. Coe ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tissue Injury ◽  
Umbilical Vein ◽  
Platelet Activating Factor ◽  
Adhesion Assay ◽  
Neutrophil Adherence ◽  
Paf Receptor ◽  
Umbilical Vein Endothelial Cells ◽  
Adhesive Effect ◽  
Paf Receptor Antagonist

Oxidants generated by endothelial xanthine oxidase (XO) can help trigger free radical-mediated tissue injury. An important event in oxidant-mediated tissue injury is neutrophil-endothelial adhesion. Although activation of endothelial XO increases adhesion, little is known about xanthine in the adhesive effect of XO. This study examined administered xanthine on the adhesion of neutrophils. Endothelial [human umbilical vein endothelial cells (HUVEC)] monolayers were exposed to xanthine (15 min), and neutrophils were allowed to adhere to HUVEC in an adhesion assay. Adhesion was dose dependently increased by xanthine (3-100 microM). Either catalase (1,000 U/ml), oxypurinol (XO inhibitor; 100 microM), or platelet-activating factor (PAF) receptor antagonist (WEB 2086; 10 microM) reduced neutrophil adhesion. Superoxide dismutase (1,000 U/ml) had no effect. Pretreatment of HUVEC with 50 microM tungsten also blocked xanthine-induced adherence. Adhesion was also inhibited by preincubation with 100 U/ml heparin. Finally, anti-P-selectin antibody (PB1.3; 20 micrograms/ml) attenuated adhesion. Our results indicate that xanthine may promote neutrophil-endothelial adhesion via a hydrogen peroxide- and PAF-mediated P-selectin expression.

scholarly journals Effect of human serum and some of its components on neutrophil adherence and migration across an epithelium.

1986 ◽  
Vol 102 (5) ◽  
pp. 1868-1877 ◽  
Author(s):  
E B Cramer ◽  
L C Milks ◽  
M J Brontoli ◽  
G K Ojakian ◽  
S D Wright ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Serum ◽  
Neutrophil Migration ◽  
Autologous Serum ◽  
Heat Inactivation ◽  
Human Neutrophils ◽  
Epithelial Surface ◽  
Neutrophil Adherence ◽  
And Migration

The effect of human serum and some of its components on the process of transepithelial migration of human neutrophils was investigated in an in vitro system. 10% autologous serum caused an increase in neutrophil adherence to and migration across canine kidney epithelial cells. This increase in neutrophil binding also occurred if the epithelium but not the neutrophils had been preincubated with serum. The binding was lost if the serum was either preabsorbed over the kidney epithelium before use or heat inactivated. Indirect immunofluorescence studies indicated that IgG, IgM, and a component of C3 bound to the epithelial surface, whereas IgA, IgE, or C5a were not detectable. The majority of epithelial cells were immunofluorescent, however epithelial cells with varying degrees of reactivity were also apparent and approximately 5% of the epithelial cells did not bind IgG, IgM, and C3. When epithelia were simultaneously tested for the presence of either IgG, IgM, or C3, and bound neutrophils the few epithelial cells which did not bind IgG or IgM also did not bind C3 or neutrophils. Studies with monoclonal antibodies against Fc and C3 receptors indicate that neutrophil adherence to the epithelial surface was mediated predominately by the receptors for C3b and C3bi. In response to a chemotactic gradient, bound neutrophils were able to detach and migrate across the epithelium. A separate heat-stable factor(s) in serum was able to increase neutrophil migration across the epithelial monolayer. This factor acted independently of the factors which caused the increase in neutrophil binding as the increase in neutrophil migration also occurred under conditions (preabsorption over the kidney epithelium or heat inactivation) that prevented the increase in neutrophil binding. The increase in neutrophil migration may be caused by the permeability-increasing properties of this factor as both serum and heat-inactivated serum lowered the transepithelial electrical resistance an average of 38 and 35%, respectively, in 40 min. Upon removal of serum or heat-inactivated serum, the resistance returned 100 and 81%, respectively, in 5 h.

scholarly journals Invasion of Human Vascular Endothelial Cells byActinobacillus actinomycetemcomitans via the Receptor for Platelet-Activating Factor

2000 ◽  
Vol 68 (9) ◽  
pp. 5416-5419 ◽  
Author(s):  
Harvey A. Schenkein ◽  
Suzanne E. Barbour ◽  
C. R. Berry ◽  
Barbara Kipps ◽  
John G. Tew
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Platelet Activating Factor ◽  
Systemic Circulation ◽  
Oral Bacteria ◽  
Periodontal Pathogen ◽  
Vascular Endothelial ◽  
Transmission Electron ◽  
Paf Receptor ◽  
Paf Receptor Antagonist

ABSTRACT Strains of the periodontal pathogen Actinobacillus actinomycetemcomitans are variable with respect to display of phosphorylcholine (PC)-bearing antigens. We have examined strains ofA. actinomycetemcomitans with and without PC to assess their ability to invade endothelial cells via the receptor for platelet-activating factor (PAF). Results of antibiotic protection assays indicate that PC-bearing A. actinomycetemcomitansinvade human vascular endothelial cells by a mechanism inhibitable by CV3988, a PAF receptor antagonist, and by PAF itself. The invasive phenotype was verified by transmission electron microscopy. A PC-deficient strain of this organism was not invasive. This property, in addition to the established ability of A. actinomycetemcomitans to invade epithelial cells, may provide this organism with access to the systemic circulation. The ability of PC-bearing oral bacteria to access the circulation may also explain the elevated levels of anti-PC antibody in serum found in patients with periodontitis.

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.

Roles for platelet-activating factor and ·NO-derived oxidants causing neutrophil adherence after CO poisoning

2001 ◽  
Vol 281 (2) ◽  
pp. H923-H930 ◽  
Author(s):  
Stephen R. Thom ◽  
Donald Fisher ◽  
Yefim Manevich
Keyword(s):  
Platelet Activating Factor ◽  
Brain Homogenate ◽  
Co Poisoning ◽  
Initial Rise ◽  
Activated Neutrophils ◽  
Neutrophil Adherence ◽  
Paf Receptor ◽  
The Brain ◽  
Qualitative Changes ◽  
Paf Receptor Antagonist

Studies were conducted with rats to investigate whether platelet activating factor (PAF) and nitric oxide (·NO)-derived oxidants played roles in the initial adherence of neutrophils to vasculature in the brain after carbon monoxide (CO) poisoning. Before CO poisoning, rats were treated with the competitive PAF receptor antagonist WEB-2170 or with the peroxynitrite scavenger selenomethionine. Both agents caused significantly lower concentrations of myeloperoxidase in the brain after poisoning, indicating fewer sequestered neutrophils. Similarly, both agents reduced the concentration of nitrotyrosine, indicating less oxidative stress due to ·NO-derived oxidants. There were no alterations in whole brain homogenate PAF concentration measured by immunoassay and bioassay, nor were there changes in phosphatidylcholine concentration. Immunohistochemical imaging showed PAF to be more heavily localized within perivascular zones after CO poisoning. Neutrophils colocalized with both PAF and nitrotyrosine in brains of rats killed immediately after CO poisoning. We conclude that qualitative changes in brain PAF are responsible for neutrophil adherence immediately after CO poisoning and that activated neutrophils trigger the initial rise in brain nitrotyrosine. Persistent PAF-mediated neutrophil adherence required production of ·NO-derived oxidants because when oxidants were scavenged, neutrophil adherence was not maintained.

Differential effects of WEB 2086 and SRI 63-441 on TNF-alpha-induced alterations in cardiopulmonary function

1992 ◽  
Vol 263 (3) ◽  
pp. H761-H770
Author(s):  
K. T. Kruse-Elliott ◽  
J. R. Dodam ◽  
L. W. Johnson ◽  
N. C. Olson
Keyword(s):  
Receptor Antagonist ◽  
Tumor Necrosis ◽  
Platelet Activating Factor ◽  
Tnf Alpha ◽  
Paf Receptor ◽  
Pulmonary Arterial ◽  
Necrosis Factor ◽  
Web 2086 ◽  
Paf Receptor Antagonist

We hypothesized that platelet-activating factor (PAF) and cyclooxygenase products might be important mediators of the cardiopulmonary effects induced by tumor necrosis factor (TNF-alpha) in anesthetized pigs. A 6-h infusion of human recombinant TNF-alpha caused hypoxemia, leukopenia, thrombocytopenia, decreased cardiac index (CI), increased pulmonary vascular resistance (PVR) and increased mean pulmonary arterial (Ppa) and intratracheal (Pt) pressures. Administration of the PAF receptor antagonist SRI 63–441 or indomethacin blocked the early (0.25–0.5 h) and attenuated the later increases in PVR and Ppa; indomethacin also attenuated the increase in Pt and hypoxemia associated with TNF-alpha infusion. WEB 2086 did not attenuate the TNF-alpha-induced alterations in CI, PVR, Pt, or PaO2. The in vivo specificity of SRI 63–441 and WEB 2086 was tested by infusing exogenous PAF, prostaglandin (PG) F2 alpha, U-46619 [thromboxane (Tx)A2 receptor mimetic], or arachidonic acid (AA) before and during administration of SRI 63–441 or WEB 2086. Both antagonists blocked the cardiopulmonary effects induced by exogenous PAF. SRI 63–441, but not WEB 2086, significantly attenuated the increased PVR caused by PGF2 alpha, U-46619, and AA. We conclude that SRI 63–441 is a less specific PAF receptor antagonist in vivo compared with WEB 2086 and that cyclooxygenase products, but not PAF, contribute significantly to the cardiopulmonary responses induced by exogenously infused TNF-alpha in pigs.

Hypoxia induces endothelial cells to increase their adherence for neutrophils: role of PAF

1992 ◽  
Vol 263 (3) ◽  
pp. H956-H962 ◽  
Author(s):  
K. A. Milhoan ◽  
T. A. Lane ◽  
C. M. Bloor
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Myocardial Ischemia ◽  
Platelet Activating Factor ◽  
Conditioned Media ◽  
Polymorphonuclear Neutrophils ◽  
Cell Monolayers ◽  
Paf Receptor ◽  
Paf Receptor Antagonist

We investigated the interactions of polymorphonuclear neutrophils (PMN) and endothelial cells in myocardial ischemia using a hypoxia model. We exposed porcine aortic (PAEC) and porcine coronary microvessel (PCMEC) endothelial cells to 2% O2 for 2 h (PO2 = 53 mmHg) and measured the adherence of unstimulated neutrophils (PMN) to both control and hypoxia-conditioned endothelial cell monolayers. Hypoxia conditioning increased PMN adherence to PAEC and PCMEC by 51 and 101%, respectively, above control levels. The increase in PMN adhesion to PAEC was associated with a threefold increase in endothelial cell-associated platelet-activating factor (PAF) compared with control PAEC. The conditioned media from PAEC exposed to hypoxia also contained sixfold more PAF than control conditioned media, and it activated PMN to become adherent to untreated PAEC. The hypoxia-induced PAEC adhesion response was inhibited by preincubating PMN with the specific PAF receptor antagonist, L-659,989. We conclude that PAF is produced by cultured endothelial cells in response to hypoxia and that PAF generation is chiefly responsible for the increased adherence properties of hypoxia-conditioned endothelial cells. This response may play a major role in regulating PMN margination during myocardial ischemia.

Mechanism of ATP-induced leukocyte adherence to cultured pulmonary artery endothelial cells

1996 ◽  
Vol 270 (5) ◽  
pp. L695-L703 ◽  
Author(s):  
A. L. Parker ◽  
L. L. Likar ◽  
D. D. Dawicki ◽  
S. Rounds
Keyword(s):  
Endothelial Cells ◽  
Cell Adhesion ◽  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Platelet Activating Factor ◽  
Human Neutrophils ◽  
Neutrophil Adherence ◽  
Human Pulmonary Artery ◽  
Pulmonary Artery Endothelial Cell ◽  
Endothelial Cell Adhesion

Previously we have shown that ATP enhances the adherence of HL-60 cells and human neutrophils to bovine pulmonary artery endothelial cells. The current investigations extend earlier findings by showing that ATP and UTP dose-dependently stimulate human neutrophil adherence to human pulmonary artery endothelial cells. We have also explore the mechanisms of ATP- and UTP-stimulated adherence. We have found that fucose, a component of selectin receptors, inhibits ATP-stimulated HL-60 cell-bovine pulmonary artery endothelial cell adhesion. Additionally, pretreatment of HL-60 cells with neuraminidase abolishes ATP enhancement. However, fucose does not affect ATP- or thrombin-induced adhesion of freshly isolated human neutrophils to human endothelial cells. Antibodies to human P-selection intercellular adhesion molecule (ICAM)-1, and the beta-subunit of CD11/CD18 do not alter ATP-induced adherence of HL-60 cells to bovine endothelial cells. Similarly, antibodies to human P-selectin and ICAM-1 do not inhibit human neutrophil-human pulmonary artery endothelial cell adhesion. The platelet-activating factor receptor antagonists, WEB-2086 and L-659,989, are effective in attenuating ATP- and UTP-stimulated adherence. Preincubation of neutrophils or human pulmonary artery endothelial cells with ATP or UTP also enhances adherence, an effect that is blocked by L-659,989. Thus platelet activating factor, associated with both neutrophils and endothelial cells, mediates ATP- and UTP-induced neutrophil adherence. ATP, released during vascular injury, may exacerbate neutrophil-endothelial cell interaction and thereby contribute to neutrophil-induced injury.

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