Differential mechanisms of plasminogen activator inhibitor-1 gene activation by transforming growth factor-beta and tumor necrosis factor-alpha in endothelial cells.
Plasminogen activator inhibitor-1 (PAI-1) is a serine protease inhibitor (SERPIN) specific for tissue-type and urokinase-like plasminogen activators. High plasma PAI-1 activity is a risk factor for thrombotic diseases. Due to the short half-life of PAI-1, regulation of PAI-1 gene expression and secretion of active PAI-1 into the blood stream is important for hemostatic balance. We have investigated transcriptional control of PAI-1 gene expression in bovine aortic endothelial cells (BAECs) and human cell lines using PAI-1 5' promoter-luciferase reporter assays. Contrary to the cytokine-induced up-regulation of PAI-1 mRNA and protein levels, we found that only transforming growth factor-beta (TGF-beta) was efficient in inducing PAI-1 promoter activation. Tissue necrosis factor-alpha (TNF-alpha) induced a small luciferase activity with the 2.5 kb PAI-1 promoter, but not with the PAI-800/4G/5G and p3TP-lux promoters. Next we investigated whether a lack of response to TNF-alpha was due to deficient signaling pathways. BAECs responded to TNF-alpha with robust NFkappaB promoter activation. TGF-beta activated the p38 MAP kinase, while TNF-alpha activated both the SAPK/JNK and p38 MAP kinases. The ERK1/2 MAP kinases were constitutively activated in BAECs. BAEC therefore responded to TNF-alpha stimulation with activation of the MAP kinases and the NFkappaB transcriptional factors. We further measured the messenger RNA stability under the influence by TGF-beta and TNF-alpha and found no difference. PAI-1 gene activation by TNF-alpha apparently is yet to be defined for the location of the response element and/or the signaling pathway, while TGF-beta is the most important cytokine for PAI-1 transcriptional activation through its 5' proximal promoter.
Chen
Y Q
YQ
Department of Cardiovascular Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA.
Sloan-Lancaster
J
J
Berg
D T
DT
Richardson
M A
MA
Grinnell
B
B
Tseng-Crank
J
J
D002478:Cells, Cultured / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D017930:Genes, Reporter; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D008156:Luciferases / Q000096:biosynthesis; D020935:MAP Kinase Signaling System / Q000187:drug effects; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000494:pharmacology; D015533:Transcriptional Activation; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases
D016328:NF-kappa B; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha; D008156:Luciferases; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases