title: alpha-Zearalanol attenuates oxLDL-induced ET-1 gene expression, ET-1 secretion and redox-sensitive intracellular signaling activation in human umbilical vein endothelial cells.
abstract: alpha-Zearalanol (alpha-ZAL), a phytochemical with both antioxidant and estrogen-like properties, has been shown to retard progression of atherosclerosis and regulate cardiovascular function in part through suppression of endothelin-1 (ET-1) secretion. However, the precise nature behind alpha-ZAL-elicited inhibition on ET-1 cascade is not largely known. Oxidized low density lipoprotein (oxLDL) plays a critical role in the expression and secretion of ET-1 as well as the onset and progression of atherosclerosis through accumulation of reactive oxygen species (ROS) and activation of mitogen-activated protein kinase stress signaling cascade. Therefore, this study was designed to examine the effect of alpha-ZAL on oxLDL-induced extracellular signal-regulated kinase (ERK) phosphorylation, ROS generation, activation of the transcriptional factor activator protein-1 (AP-1), expression, secretion and promoter activity of ET-1 in human umbilical vein endothelial cells (HUVEC). ROS generation was monitored using 2,7-dichlorofluorescin fluorescence. ET-1 expression and promoter activity were evaluated by RT-PCR and luciferase assays, respectively. oxLDL (35 microg/ml) significantly enhanced ERK phosphorylation, ROS generation, AP-1 activity, mRNA expression, secretion and promoter activity of ET-1 in HUVECs, all of which were abrogated by alpha-ZAL and the antioxidant N-acetyl-l-cysteine. Collectively, these data favor the notion that alpha-ZAL antagonizes oxLDL-induced upregulation of ET-1 gene expression and secretion via suppression of oxLDL-induced ROS accumulation, ERK phosphorylation, and activation of the endothelial transcriptional factor AP-1.
authors.affiliation: Faculty of Basic Medicine, Peking Union Medical College, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing, PR China.
authors.forename: Haishan
authors.initials: H
authors.lastname: Xu
authors.forename: Jinhong
authors.initials: J
authors.lastname: Duan
authors.forename: Shunling
authors.initials: S
authors.lastname: Dai
authors.forename: Yunqing
authors.initials: Y
authors.lastname: Wu
authors.forename: Renyu
authors.initials: R
authors.lastname: Sun
authors.forename: Jun
authors.initials: J
authors.lastname: Ren
mesh_terms: D002478:Cells, Cultured; D004338:Drug Combinations; D019332:Endothelin-1 / Q000235:genetics*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014471:Umbilical Veins / Q000166:cytology / Q000378:metabolism; D015029:Zeranol / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D004338:Drug Combinations; D019332:Endothelin-1; D008077:Lipoproteins, LDL; D017382:Reactive Oxygen Species; D018808:Transcription Factor AP-1; C099252:oxidized low density lipoprotein; C029659:zearalenol; D015029:Zeranol; D048049:Extracellular Signal-Regulated MAP Kinases