title: LOX-1 receptor blockade abrogates oxLDL-induced oxidative DNA damage and prevents activation of the transcriptional repressor Oct-1 in human coronary arterial endothelium.
abstract: Activation of the lectin-like oxLDL receptor (LOX-1) promotes atherosclerosis. Oxidized LDL (oxLDL) increases production of reactive oxygen species (ROS) and leads to the development of endothelial dysfunction. The molecular causes for oxLDL to induce oxidative DNA damage and metabolic dysfunction remain uncertain. Here we report treatment of cultured human coronary arterial endothelial cells (HCAEC) with oxLDL to cause oxidative DNA damage as determined by a 3-fold increase in 8-OH-desoxyguanosine adduct formation and a 4-fold induction of the growth arrest and DNA damage-inducible transcripts GADD45 and GADD153. Oxidative stress resulted in activation of Oct-1, a transcriptional repressor of various vascular cytochrome P450 (CYP) monooxygenases. Activation of Oct-1 was protein kinase C (PKC)-mediated. Binding of Oct-1 to promoter sequences of CYP monooxygenases was increased upon treatment of HCAEC with oxLDL. This resulted in repressed production of endothelium-derived hyperpolarization factor 11,12-epoxyeicosatrieonic acid. Small interference RNA-mediated functional knockdown of Oct-1 prevented oxLDL-mediated silencing of CYP expression. Inhibition of LOX-1 attenuated oxLDL-mediated endothelial DNA damage, Oct-1/DNA binding, and reversed impaired production of EDHF. Taken collectively, oxLDL induced oxidative DNA damage and activation of Oct-1 to result in metabolic dysfunction of coronary arterial endothelium.
authors.affiliation: Medizinische Klinik I, Kardiologie, Julius-Maximilians Universität, Josef-Schneider-Strasse 2, 97080 Würzburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Thum
authors.forename: Jürgen
authors.initials: J
authors.lastname: Borlak
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D000080242:8-Hydroxy-2'-Deoxyguanosine; D001685:Biological Factors / Q000096:biosynthesis; D018797:Cell Cycle Proteins / Q000378:metabolism; D002478:Cells, Cultured; D003324:Coronary Artery Disease / Q000378:metabolism / Q000473:pathology; D003331:Coronary Vessels / Q000378:metabolism* / Q000473:pathology; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis; D018736:DNA Adducts / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D004730:Endothelium, Vascular / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism* / Q000494:pharmacology; D009687:Nuclear Proteins / Q000378:metabolism; D050811:Octamer Transcription Factor-1 / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D020218:Response Elements; D051127:Scavenger Receptors, Class E / Q000819:agonists / Q000378:metabolism*; D051742:Transcription Factor CHOP / Q000378:metabolism; D000097642:GADD45 Proteins
chemical_list: D015126:8,11,14-Eicosatrienoic Acid; D000080242:8-Hydroxy-2'-Deoxyguanosine; D001685:Biological Factors; D018797:Cell Cycle Proteins; D003577:Cytochrome P-450 Enzyme System; D018736:DNA Adducts; D003849:Deoxyguanosine; D008077:Lipoproteins, LDL; D009687:Nuclear Proteins; D050811:Octamer Transcription Factor-1; D011493:Protein Kinase C; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D012097:Repressor Proteins; D051127:Scavenger Receptors, Class E; D051742:Transcription Factor CHOP; C497249:DDIT3 protein, human; C439070:GADD45A protein, human; D000097642:GADD45 Proteins; C495137:OLR1 protein, human; C494165:POU2F1 protein, human; C067410:endothelium-dependent hyperpolarization factor; C099252:oxidized low density lipoprotein; C046783:11,12-epoxy-5,8,14-eicosatrienoic acid