Inhibitory effect of polyphenol cyanidin on TNF-alpha-induced apoptosis through multiple signaling pathways in endothelial cells.
The aim of this study was to investigate the inhibitory effect of non-aglycone cyanidin on TNF-alpha-induced endothelial cell apoptosis and its mechanism through enhancing expression of thioredoxin in endothelial cells. We found that exposure of the serum-starved BAECs to TNF-alpha increased significantly the number of dead cells, the cleaved caspase-3 and cleaved poly(ADP-ribose)polymerase (RARP)assayed by Western blot, whereas supplementation with cyanidin considerably suppressed these events. Inhibitors of the Akt, ERK1/2, Src kinase and transfection with a dominant-negative Akt cDNA blocked the inhibitory effect of cyanidin on cleaved caspase-3. Cyanidin significantly elevated expression of endothelial nitric oxide synthase (eNOS) and thioredoxin (Trx). The increased Trx expression was blocked by siRNA transfection of cGMP-dependent protein kinase (PKG) and by using a PKG inhibitor, KT5823. Cyanidin also ameliorated TNF-alpha-induced decrease of Trx S-nitrosylation and intracellular glutathione and elevation of 4-hydroxynonenal (4-HNE), a major aldehydic product of lipid peroxidation. Furthermore, cyanidin also restored S-nitrosylation of caspase-3 and reduced the rise in expression and acetylation of tumor suppression gene p53. However, KT5823 or L-NAME, an inhibitor of eNOS, removed the preventive effects of cyanidin. Our data show that inhibitory effect of cyanidin on TNF-alpha-induced apoptosis involves multiple pathways, such as Akt activation, eNOS and thioredoxin expression in endothelial cells.
Xu
Jin-Wen
JW
Frontier Health Science, School of Human Environmental Science, MUKOGAWA Women's University, Nishinomiya, Hyogo 663-8179, Japan. jwxu@mukogawa-u.ac.jp
Ikeda
Katsumi
K
Yamori
Yukio
Y
D000818:Animals; D000872:Anthocyanins / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000276:immunology; D002417:Cattle; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects* / Q000276:immunology; D005419:Flavonoids / Q000494:pharmacology*; D051379:Mice; D019001:Nitric Oxide Synthase / Q000096:biosynthesis; D018384:Oxidative Stress / Q000187:drug effects / Q000276:immunology; D010636:Phenols / Q000494:pharmacology*; D059808:Polyphenols; D051057:Proto-Oncogene Proteins c-akt / Q000096:biosynthesis; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology; D013879:Thioredoxins / Q000096:biosynthesis; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
D000872:Anthocyanins; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D014409:Tumor Necrosis Factor-alpha; D013879:Thioredoxins; C017154:cyanidin; D019001:Nitric Oxide Synthase; D051057:Proto-Oncogene Proteins c-akt