Evidence for protein-catalyzed transfer of platelet activating factor by macrophage cytosol

Banks, J.; Wykle, Robert L.; O’Flaherty, Joseph T.; Lumb, Roger H.

doi:10.1016/0005-2760(88)90129-4

Cited by 35 publications

(13 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…PAF is synthesized in an intracellular membranous organelle, presumably the ER. A portion of the newly synthesized PAF is then rapidly transported to the inner leaflet of the plasma membrane by a phospholipid transport protein (Bishop and Bell, 1988), shown in A; putative PAF transport proteins have been identified in other cell types (Banks et al, 1988). A "flippase" (Bishop and Bell, 1988) catalyzes the rapid transmembrane transfer of PAF to the outer leaflet of the plasma membrane where PAF is localized in the phospholipid milieu (position 1) or by noncovalent binding to one or more surface proteins (position 2).…”

Section: Discussionmentioning

confidence: 99%

Endothelial cell-associated platelet-activating factor: a novel mechanism for signaling intercellular adhesion.

Zimmerman

McIntyre

Mehra

et al. 1990

The Journal of Cell Biology

358

153

View full text Add to dashboard Cite

Abstract. The binding of neutrophils (polymorphonuclear leukocytes [PMNs]) to endothelial cells (ECs) presents special requirements in the regulation of intercellular adhesion. ECs that are stimulated by certain agonists, including thrombin and cytokines (tumor necrosis factor or, interleukin-1), generate molecular signals that induce the adhesion of PMNs (endothelial cell-dependent neutrophil adhesion). Our experiments demonstrate that the mechanism of binding induced by thrombin is distinct from that induced by the cytokines based on the time courses, the requirement for protein synthesis, and differential binding of HL60 promyelocytic leukemia cells to ECs activated by the two classes of agonists. The rapid EC-dependent PMN adhesion (initiated in minutes) that occurs when the ECs are stimulated by thrombin is temporally coupled with the accumulation of platelet-activating factor, a biologically active phosphoglyceride that remains associated with ECs and that activates PMNs by binding to a cell surface receptor. A portion of the newly synthesized plateletactivating factor (PAF) is on the EC surface, as demonstrated by experiments in which the rate of hydrolysis of PAF synthesized by activated ECs was accelerated by extracellular PAF acetylhydrolase. When ECs were treated with exogenous PAF they became adhesive for PMNs; the PMN binding was prevented by incubating the ECs with PAF acetylhydrolase or by treating the PMNs with competitive PAF receptor antagonists. Thus PAF associated with the EC plasma membrane induces PMN binding, an observation supported by experiments in which PAF in model membranes (liposomes) stimulated rapid PMN adhesion to ECs and to cell-free surfaces. In addition, competitive antagonists of the PAF receptor inhibited the binding of PMNs to ECs activated by thrombin and other rapidly acting agonists, but not to ECs activated by tumor necrosis factor c~, indicating that PAF that is endogenously synthesized by ECs can mediate neutrophil adhesion. These experiments demonstrate a novel mechanism by which a cell-associated phospholipid, PAF, can serve as a signal for an intercellular adhesive event.

show abstract

Section: Discussionmentioning

confidence: 99%

Endothelial cell-associated platelet-activating factor: a novel mechanism for signaling intercellular adhesion.

Zimmerman

McIntyre

Mehra

et al. 1990

The Journal of Cell Biology

358

153

View full text Add to dashboard Cite

show abstract

“…4). It was suggested that PAF produced in the microsornes is trans-ported to the membrane by a specific protein (Banks et al, 1988). Using the same technique, we demonstrated that 20% PAF produced after treatment with TNF-a and IL-la is exposed on the EC surface (Bussolino et al, 1994a).…”

Section: Localization Of the Paf Producedmentioning

confidence: 69%

Platelet-Activating Factor Produced by Endothelial Cells. A Molecule with Autocrine and Paracrine Properties

Bussolino

Camussi

1995

Eur J Biochem

View full text Add to dashboard Cite

Endothelial cells (EC) participate in microenvironment homeostasis by regulating the trafficking of cells and molecules from the bloodstream to the tissues. The 'area codes' used to control the trafficking are adhesion molecules, receptors which pick up external signals, and mediators of cell-to-cell communication. Platelet-activating factor (PAF) is a mediator that belongs to this class of 'area-code' molecules. PAF is an acetylated derivative of phosphatidylcholine which is produced by EC and may act in an autocrine manner. Several stimuli may induce the synthesis of PAF by EC with different time courses. Thrombin, elastase and tumor necrosis factor (TNF) are prototypic molecules inducing very-early, early and delayed PAF synthesis, respectively. These stimuli activate the 'remodelling pathway' which requires the activation of phospholipase A2 and acetyl CoA:1-alkyl-2-lyso-sn-glycero-3-phosphate acetyltransferase. The effects of very-early and early stimuli are mediated by a direct stimulation of this pathway, whereas the action of TNF is mediated by the new synthesis of a serine protease. Stimulated EC produce PAF molecules with both an ether and an ester bond at the sn-1 position, but the former is predominant. The PAF produced is partially exposed on the external membranes and participates in adhesion or migration of neutrophils. PAF released can also stimulate EC themselves, by interacting with a specific receptor. PAF stimulates the migration and the shape change of EC by activating calcium influx and several serine/threonine and tyrosine kinases which regulate the cytoskeleton.

show abstract

“…The time scale of these experiments was too short to determine the tl12 values for pyrPC, but these will be on the order of hours to days as has been determined by others (Homan & Pownall, 1988;Hresko et al, 1985). In control experiments, the spontaneous transfer of [3H]3dTDP-DG from donor vesicles to multilamellar liposomes consisting of egg PC/cholesterol/DMPA (6:3:1 mol/mol) was determined according to Banks et al (1988). A tllz value of 20-30 min at 37 O C was found, confirming that the relatively high rate of spontaneous transfer for this type of compound is not a peculiar property of the pyrene-labeled analog.…”

Section: Rwults and Discussionmentioning

confidence: 99%

Spontaneous and protein-mediated intermembrane transfer of the antiretroviral liponucleotide 3'-deoxythymidine diphosphate diglyceride

Gadella¹,

Wirtz²,

Hostetler³

et al. 1992

Biochemistry

View full text Add to dashboard Cite

Evidence for protein-catalyzed transfer of platelet activating factor by macrophage cytosol

Cited by 35 publications

References 12 publications

Endothelial cell-associated platelet-activating factor: a novel mechanism for signaling intercellular adhesion.

Endothelial cell-associated platelet-activating factor: a novel mechanism for signaling intercellular adhesion.

Platelet-Activating Factor Produced by Endothelial Cells. A Molecule with Autocrine and Paracrine Properties

Spontaneous and protein-mediated intermembrane transfer of the antiretroviral liponucleotide 3'-deoxythymidine diphosphate diglyceride

Contact Info

Product

Resources

About