Phytoestrogen genistein up-regulates endothelial nitric oxide synthase expression via activation of cAMP response element-binding protein in human aortic endothelial cells.
We previously reported that genistein, a phytoestrogen, up-regulates endothelial nitric oxide synthase (eNOS) and prevents hypertension in rats that are independent of estrogen signaling machinery. However, how genistein regulates eNOS expression is unknown. In the present study, we show that genistein enhanced eNOS expression and NO synthesis in primary human aortic endothelial cells. Inhibition of extracellular signal regulated kinase, phosphoinositol-3 kinase, or protein kinase C did not affect genistein-enhanced eNOS expression and NO synthesis. However, chemical inhibition of protein kinase A (PKA) or adenoviral transfer of the specific endogenous PKA inhibitor gene completely abolished PKA activity and genistein-stimulated eNOS expression and NO production. Accordingly, genistein induced PKA activity and subsequent phosphorylation of cAMP response element (CRE)-binding protein (CREB) at Ser133. Suppression of CREB by small interfering RNA transfection abolished genistein-enhanced eNOS expression and NO production. Consistently, deletion of the CRE site within human eNOS promoter eliminated genistein-stimulated eNOS promoter activity. These findings provide the first evidence to our knowledge that genistein may play a beneficial role in vascular function through targeting the PKA/CREB/eNOS/NO signaling pathway.
Department of Human Nutrition, Foods, and Exercise, College of Agriculture and Life Sciences, Virginia Tech, Blacksburg, Virginia 24061, USA.
Hongwei
H
Si
Jie
J
Yu
Hongling
H
Jiang
Hazel
H
Lum
Dongmin
D
Liu
D001011:Aorta / Q000473:pathology*; D001665:Binding Sites; D017362:Cyclic AMP Response Element-Binding Protein / Q000096:biosynthesis*; D042783:Endothelial Cells / Q000166:cytology*; D017353:Gene Deletion; D005786:Gene Expression Regulation; D019833:Genistein / Q000494:pharmacology*; D006801:Humans; D052250:Nitric Oxide Synthase Type III / Q000096:biosynthesis*; D010766:Phosphorylation; D048789:Phytoestrogens / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D034741:RNA, Small Interfering / Q000378:metabolism; D012694:Serine / Q000737:chemistry; D015398:Signal Transduction; D015854:Up-Regulation
D017362:Cyclic AMP Response Element-Binding Protein; D048789:Phytoestrogens; D034741:RNA, Small Interfering; D012694:Serine; D019833:Genistein; D052250:Nitric Oxide Synthase Type III