title: Thrombin induces endothelin expression in arterial smooth muscle cells.
abstract: Thrombin has been shown to stimulate endothelin release by endothelial cells, but the ability of thrombin to induce endothelin in nonendothelial cells is less well-known. Incubation of rat aortic smooth muscle cells with thrombin resulted in a stimulation of preproendothelin-1 (preproET-1) mRNA expression. This induction of preproET-1 mRNA expression by thrombin was accompanied by the release of immunoreactive peptide ET-1 into the extracellular medium. The synthetic thrombin receptor activator peptide (TRAP) confirmed ligand-specific receptor action to induce preproET-1 mRNA. Nuclear run-on analysis revealed that the transcriptional rate of preproET-1 mRNA increases twofold after 1 h of incubation with thrombin. In cells treated with thrombin, the half-life of preproET-1 mRNA was identical to that in untreated control cells. These results demonstrated that thrombin regulates endothelin synthesis at a transcriptional level but does not influence mRNA stability. Inhibition of protein kinase C (PKC) with selective inhibitors (chelerythrine and bisindolylmaleimide I) before thrombin stimulation failed to significantly inhibit preproET-1 gene expression. Inhibition of mitogen-activated protein (MAP) kinase kinase and protein tyrosine kinase decreased preproET-1 mRNA expression in thrombin-stimulated smooth muscle cells. Furthermore, addition of an activator of peroxisome proliferator-activated receptors-alpha (PPARalpha), fenofibrate, prevented the preproET-1 gene induction in response to thrombin. These results demonstrated that thrombin-induced endothelin gene transcription involved MAP kinase kinase rather than the PKC cascade in smooth muscle cells, which was repressed by PPARalpha stimulation.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale U460, UFR X. Bichat, 75018 Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Lepailleur-Enouf
authors.forename: O
authors.initials: O
authors.lastname: Valdenaire
authors.forename: M
authors.initials: M
authors.lastname: Philippe
authors.forename: M
authors.initials: M
authors.lastname: Jandrot-Perrus
authors.forename: J B
authors.initials: JB
authors.lastname: Michel
mesh_terms: D000818:Animals; D001011:Aorta; D001158:Arteries / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000235:genetics / Q000378:metabolism; D016232:Endothelins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D016014:Linear Models; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010446:Peptide Fragments / Q000494:pharmacology; D011493:Protein Kinase C / Q000187:drug effects / Q000378:metabolism; D011498:Protein Precursors / Q000096:biosynthesis* / Q000235:genetics; D011506:Proteins / Q000494:pharmacology; D012319:RNA Polymerase II / Q000037:antagonists & inhibitors; D020871:RNA Stability / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D044463:Receptor, PAR-1; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D018179:Receptors, Thrombin / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013917:Thrombin / Q000378:metabolism* / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D019332:Endothelin-1; D016232:Endothelins; D004791:Enzyme Inhibitors; D010446:Peptide Fragments; D011498:Protein Precursors; D011506:Proteins; D012333:RNA, Messenger; D044463:Receptor, PAR-1; D018160:Receptors, Cytoplasmic and Nuclear; D018179:Receptors, Thrombin; D014157:Transcription Factors; D011493:Protein Kinase C; D012319:RNA Polymerase II; D013917:Thrombin; D013755:Tetradecanoylphorbol Acetate