title: Peroxide-inducible Ets-1 mediates platelet-derived growth factor receptor-alpha gene transcription in vascular smooth muscle cells.
abstract: Platelet-derived growth factor (PDGF) has been implicated in the pathogenesis of vascular occlusive disorders such as atherosclerosis and restenosis in part due to its regulation of smooth muscle cell phenotype. The molecular mechanisms regulating the expression of PDGF-Ralpha, which binds all known dimeric forms of PDGF except PDGF-DD, are poorly understood. Here we demonstrate that the winged helix-turn-helix proto-oncogene Ets-1 controls PDGF-Ralpha transcription and mRNA expression in smooth muscle cells. Mutational analysis, electrophoretic mobility shift assay, and chromatin immunoprecipitation revealed the existence of a reverse Ets binding motif (-45TTCC-42) in the proximal region of the PDGF-Ralpha promoter, which bound both recombinant and endogenous Ets-1. Ets-1-inducible PDGF-Ralpha expression depended on the integrity of both the -45TTCC-42 motif and the -61G10(-52) element, which resides upstream of -45TTCC-42 and mediates Sp1 induction. Hydrogen peroxide (H2O2) at nanomolar concentrations stimulated levels of Ets-1 and increased PDGF-Ralpha transcription and mRNA expression without affecting Sp1 expression. H2O2 activation of the PDGF-Ralpha promoter was abolished by disrupting -45TTCC-42 or -61G10(-52). These studies identify a functional Ets motif in the PDGF-Ralpha promoter that plays a pivotal role in agonist-inducible PDGF-Ralpha transcription.
authors.affiliation: Centre for Vascular Research, Department of Pathology, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Bonello
authors.forename: Yuri V
authors.initials: YV
authors.lastname: Bobryshev
authors.forename: Levon M
authors.initials: LM
authors.lastname: Khachigian
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D001161:Arteriosclerosis / Q000378:metabolism / Q000473:pathology; D015153:Blotting, Western; D002339:Carotid Arteries / Q000473:pathology; D049109:Cell Proliferation; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D004305:Dose-Response Relationship, Drug; D024202:Electrophoretic Mobility Shift Assay; D017930:Genes, Reporter; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008156:Luciferases / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009154:Mutation; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D000090063:Proto-Oncogene Mas; D050784:Proto-Oncogene Protein c-ets-1 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011921:Rats, Inbred WKY; D017479:Receptors, Platelet-Derived Growth Factor / Q000235:genetics*; D016329:Sp1 Transcription Factor / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: C494041:ETS1 protein, human; C000715470:MAS1 protein, human; D016376:Oligonucleotides, Antisense; D016877:Oxidants; D000090063:Proto-Oncogene Mas; D050784:Proto-Oncogene Protein c-ets-1; D012333:RNA, Messenger; D016329:Sp1 Transcription Factor; D006861:Hydrogen Peroxide; D008156:Luciferases; D017479:Receptors, Platelet-Derived Growth Factor