Cytokine activation of vascular endothelium. Effects on tissue-type plasminogen activator and type 1 plasminogen activator inhibitor.
Regulation of the fibrinolytic system of cultured human umbilical vein endothelial cells (HUVECs) by recombinant interleukin 1 beta (rIL-1 beta) and tumor necrosis factor alpha (rTNF alpha) was investigated. Functional and immunologic assays indicated that both cytokines decreased HUVEC tissue-type plasminogen activator (tPA) and increased type 1 plasminogen activator inhibitor (PAI-1) in a dose- and time-dependent manner. Maximal effects (50% decrease in tPA antigen; 300-400% increase in PAI-1 activity) were achieved with 2.5 units/ml rIL-1 beta and 200 units/ml rTNF alpha. Combinations of rIL-1 beta and rTNF alpha were not additive at these maximal concentrations. After a 24-h pretreatment with rIL-1 beta, HUVECs secreted tPA at one-quarter of the rate of control cells and released PAI-1 at a rate that was 5-fold higher than controls. Neither the basal rate of PAI-1 release nor the increased rate of release of PAI-1 in response to rIL-1 beta was affected by subsequently treating the cells with secretagogues (e.g. phorbol myristate acetate) suggesting that PAI-1 is not contained within a rapidly releasable, intracellular storage pool. Northern blot analysis using a PAI-1 cDNA probe indicated that the cytokines increased the steady-state levels of the 3.2- and 2.3-kb PAI-1 mRNA species, but with a preferential increase in the larger mRNA form. The fact that both rIL-1 beta and rTNF alpha act in a similar manner strengthens the hypothesis that the local development of inflammatory/immune processes could reduce endothelial fibrinolytic activity.
D000001:Calcimycin / Q000494:pharmacology; D002478:Cells, Cultured; D004347:Drug Interactions; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000378:metabolism*; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007118:Immunoassay; D007375:Interleukin-1 / Q000494:pharmacology*; D007700:Kinetics; D015849:Plasminogen Inactivators; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D010959:Tissue Plasminogen Activator / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014471:Umbilical Veins
D006023:Glycoproteins; D007375:Interleukin-1; D015849:Plasminogen Inactivators; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D000001:Calcimycin; D010959:Tissue Plasminogen Activator; D013755:Tetradecanoylphorbol Acetate