E-selectin and intercellular adhesion molecule-1 are released by activated human endothelial cells in vitro.
Endothelial cells respond to several cytokines by a rapid increase in expression of the adhesion molecules E-selectin and intercellular adhesion molecule-1 (ICAM-1), followed by a gradual decline. The fate of these molecules, which was so far unknown, was studied. Specific sandwich ELISA for the detection of soluble (s)E-selectin and sICAM-1 were developed. In supernatant, centrifuged 3 hr at 100,000 g to remove microparticles, from human umbilical vein endothelial cells (HUVEC) activated with tumour necrosis factor (TNF), interleukin-1 (IL-1) or lipopolysaccharide (LPS), E-selectin and ICAM-1 molecules could be detected. Biochemical analysis revealed that sE-selectin migrated as a band of approximately 94,000 MW. The amount of soluble adhesion molecules released was directly correlated with cell surface expression. Maximal release of E-selectin was observed 6-12 hr after activation of HUVEC and decreased to below detection limit 24 hr after activation. After activation, release of ICAM-1 gradually increased with ICAM-1 cell surface expression, and reached a plateau after 24 hr, which was constant for 3 days. Since E-selectin and ICAM-1 are highly expressed at inflammatory sites, the resulting high concentrations of released E-selectin and ICAM-1 may affect interactions of leucocytes with endothelial cells. The physiological role, however, of the release of E-selectin and ICAM-1 remains to be elucidated.
Leeuwenberg
J F
JF
Department of Surgery, University of Limburg, Maastricht, The Netherlands.
Smeets
E F
EF
Neefjes
J J
JJ
Shaffer
M A
MA
Cinek
T
T
Jeunhomme
T M
TM
Ahern
T J
TJ
Buurman
W A
WA
D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D019040:E-Selectin; D004730:Endothelium, Vascular / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D018799:Intercellular Adhesion Molecule-1; D007700:Kinetics
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015815:Cell Adhesion Molecules; D019040:E-Selectin; D018799:Intercellular Adhesion Molecule-1