title: Green tea polyphenols inhibit plasminogen activator inhibitor-1 expression and secretion in endothelial cells.
abstract: Compelling epidemiological evidence suggests that the consumption of green tea is associated with beneficial effects in prevention of cardiovascular diseases. Plasminogen activator inhibitor-1 (PAI-1) is known to play a pivotal role in cardiovascular diseases including arteriosclerosis and hypertension. Increased PAI-1 was found in atherosclerotic lesions, and high PAI-1 plasma levels were associated with coronary heart disease. To determine the effect and molecular mechanism of green tea polyphenols (GTPs) on the regulation of PAI-1 expression in endothelial cells, bovine aortic endothelial cells were incubated with GTPs, and PAI-1 expressions were measured by western blot and enzyme-linked immunosorbent assay, respectively. GTPs significantly reduced PAI-1 expression and secretion in a time-dependent and dose-dependent manner. Inhibition of phosphatidylinositol 3-kinase (PI3K) with wortmannin markedly reversed GTPs repression of PAI-1 expression. In addition, the GTP-induced inhibitory effect was associated with an increased of activation of the protein kinase Akt. These results suggest that GTPs inhibit PAI-1 expression and its release from endothelial cells through the PI3K/Akt pathway, which may contribute to cardiovascular protection.
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.forename: Chenjiang
authors.initials: C
authors.lastname: Ying
authors.forename: Yi
authors.initials: Y
authors.lastname: Meng
authors.forename: Weijie
authors.initials: W
authors.lastname: Yi
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Fan
authors.forename: Xuezhi
authors.initials: X
authors.lastname: Zuo
authors.forename: Chong
authors.initials: C
authors.lastname: Tian
authors.forename: Xiufa
authors.initials: X
authors.lastname: Sun
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology; D005419:Flavonoids / Q000493:pharmacokinetics / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D010636:Phenols / Q000493:pharmacokinetics / Q000494:pharmacology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics* / Q000378:metabolism; D059808:Polyphenols; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D013662:Tea / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D010636:Phenols; D017395:Plasminogen Activator Inhibitor 1; D059808:Polyphenols; D013662:Tea; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt