Inhibition of platelet endothelial cell adhesion molecule-1 synthesis and leukocyte transmigration in endothelial cells by the combined action of TNF-alpha and IFN-gamma.
Endothelial cell (EC) junctions regulate circulating leukocyte extravasation and infiltration at inflammatory sites. Several lines of evidence show that platelet endothelial cell adhesion molecule-1 (PECAM-1), a specific component of EC junctions, is required for leukocyte transmigration through EC monolayers. In this paper, we examined the effects of two inflammatory cytokines, TNF-alpha and IFN-gamma, on PECAM-1 and vascular endothelial-cadherin/catenin organization. We found that the addition of inflammatory cytokines (TNF-alpha plus IFN-gamma in combination, for > or = 24 h) caused PECAM-1 to disappear from EC intercellular contacts. Confocal microscopy indicated that after treatment with the cytokines, PECAM-1 was rapidly internalized. In addition, a strong inhibition of PECAM-1 synthesis and a decrease in PECAM-1 mRNA were observed. This phenomenon was only found when TNF-alpha plus IFN-gamma were used in combination. Adhesion of polymorphonuclear cells to doubly treated EC was increased compared with control cells or cells incubated with TNF-alpha or IFN-gamma separately. This was correlated with an increased expression of intercellular adhesion molecule-1. However, the disappearance of PECAM-1 from cell junctions after treatment with TNF-alpha plus IFN-gamma was accompanied by a marked reduction of leukocyte migration through EC monolayers. The correlation between PECAM-1 level and leukocyte transmigration was supported by transmigration inhibition assays using blocking anti-PECAM-1 mAb. These data indicate that PECAM-1 is a specific target of inflammatory cytokines and suggest that changes in its synthesis and organization might negatively modulate leukocyte recruitment.
Rival
Y
Y
Atomic Energy Commission, Laboratory of Hematology, INSERM Unit 217, Department of Molecular and Structural Biology, Center for Nuclear Studies (CEN), Grenoble, France.
Del Maschio
A
A
Rabiet
M J
MJ
Dejana
E
E
Duperray
A
A
D000818:Animals; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic / Q000096:biosynthesis* / Q000235:genetics; D015152:Blotting, Northern; D015820:Cadherins / Q000494:pharmacology; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000096:biosynthesis* / Q000235:genetics; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D051379:Mice; D018613:Microscopy, Confocal; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D000099152:Cadherin 5
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015820:Cadherins; D015815:Cell Adhesion Molecules; D007371:Interferon-gamma; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D014409:Tumor Necrosis Factor-alpha; D000099152:Cadherin 5