Cultured human vascular endothelial cells acquire adhesiveness for neutrophils after stimulation with interleukin 1, endotoxin, and tumor-promoting phorbol diesters.
Cultured human vascular endothelial cells obtained from umbilical cord veins were observed to acquire adhesive properties for purified neutrophils after exposure to IL 1, endotoxin, and tumor-promoting phorbol diesters. Adhesiveness induced by IL1 and endotoxin had similar kinetics of onset, producing no change after 30 min incubation and reaching optimal change by 4 hr of incubation. The phorbol diester TPA induced changes in adhesiveness more rapidly, with half maximal increase induced by a 15- to 30-min exposure. TPA, but not IL 1 or LPS, induced significant morphologic changes in the endothelial cell monolayer. None of the stimuli decreased endothelial cell viability. All stimuli induced increased adhesiveness at relevant concentrations, i.e., endotoxin, 0.01 to 1 microgram/ml; IL 1, 0.5 to 2 U/ml; and TPA, 1 to 30 ng/ml. Structure activity relationships among phorbol diesters indicate that the response occurs through a typical phorbol diester "receptor." A protein synthesis inhibitor (cycloheximide) and an RNA synthesis inhibitor (actinomycin D) prevented the acquisition of adhesiveness stimulated by IL 1 and endotoxin but not by TPA. In addition, TPA showed a differential temperature sensitivity in inducing adhesiveness in endothelial cells. IL 1 and endotoxin did not produce the effect with a 4-hr incubation at 22 degrees or 4 degrees C, whereas TPA was effective at these lower temperatures. Purified human IL 2 and recombinant-derived interferon-gamma failed to induce adhesiveness in vascular endothelial cells, indicating that this is not a general property of lymphokines. We conclude that endothelium may, under some circumstances, play an active role in producing a leukocyte infiltrate at a local tissue site by acquiring adhesive properties. The production of IL 1 by tissue macrophages, etc., may serve as an important initiator of an inflammatory cell infiltrate. Finally, an action of tumor-promoting phorbol diesters in increasing endothelial cell adhesiveness, combined with their known effects in activating leukocytes, may help explain the extraordinary inflammatory potency of these compounds.
Schleimer
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Rutledge
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BK
D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004727:Endothelium / Q000166:cytology / Q000502:physiology; D004731:Endotoxins / Q000502:physiology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000502:physiology*; D007376:Interleukin-2 / Q000502:physiology; D007700:Kinetics; D009504:Neutrophils / Q000502:physiology*; D010704:Phorbols / Q000494:pharmacology*; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis; D013696:Temperature; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014471:Umbilical Veins
D004731:Endotoxins; D007375:Interleukin-1; D007376:Interleukin-2; D010704:Phorbols; D012313:RNA; D007371:Interferon-gamma; D013755:Tetradecanoylphorbol Acetate