title: Thrombin induction of plasminogen activator inhibitor mRNA in human umbilical vein endothelial cells in culture.
abstract: We have previously reported that incubation of human umbilical vein endothelial cells (HUVECs) with human alpha-thrombin causes a time- and concentration-dependent increase in secreted plasminogen activator inhibitor type 1 (PAI-1) activity (Gelehrter TD, Sznycer-Laszuk R. J Clin Invest 1986;77:165-9). Here we report that the regulation of PAI-1 activity by thrombin is secondary to the thrombin-induced increase in PAI-1 mRNA accumulation. Incubation of HUVECs for 6 to 24 hours with 0.3 to 1.0 U/ml thrombin causes a 1.8-fold to 10-fold increase in PAI-1 activity and a 1.5-fold to threefold increase in accumulation of both the 3.2 and the 2.2 kilobase PAI-1 mRNAs. These effects are prevented by the prior addition of hirudin, a specific thrombin inhibitor. Inhibition of RNA synthesis with actinomycin D blocks the thrombin induction of PAI-1 mRNA accumulation. The protein synthesis inhibitor, cycloheximide, which itself markedly stimulates the accumulation of PAI-1, appears to prevent the induction by thrombin, suggesting that thrombin may act by inducing another effector such as interleukin-1. Consistent with this hypothesis is our observation that simultaneous addition of antibodies to interleukin-1-alpha prevents the thrombin induction of PAI-1 activity and mRNA.
authors.affiliation: Department of Human Genetics, University of Michigan Medical School, Ann Arbor 48109-0618.
authors.forename: J H
authors.initials: JH
authors.lastname: Heaton
authors.forename: M K
authors.initials: MK
authors.lastname: Dame
authors.forename: T D
authors.initials: TD
authors.lastname: Gelehrter
mesh_terms: D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D007700:Kinetics; D015849:Plasminogen Inactivators / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D014471:Umbilical Veins
chemical_list: D007375:Interleukin-1; D015849:Plasminogen Inactivators; D012333:RNA, Messenger; D011994:Recombinant Proteins; D003609:Dactinomycin; D003513:Cycloheximide; D013917:Thrombin; D010959:Tissue Plasminogen Activator