Klinge Carolyn M, Wickramasinghe Nalinie S, Ivanova Margarita M, Dougherty Susan M
Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY 40292, USA.
FASEB J. 2008 Jul;22(7):2185-97. doi: 10.1096/fj.07-103366. Epub 2008 Feb 22.
Epidemiological studies correlate moderate red wine consumption to reduced incidence of cardiovascular disease. Resveratrol is a polyphenolic compound in red wine that has cardioprotective effects in rodents. Although endothelial cell (EC) studies indicate that micromolar resveratrol has diverse biological activities, these concentrations are not physiologically relevant because human oral ingestion provides only brief exposure to nanomolar plasma levels. Previously, we reported that nanomolar resveratrol activated ERK1/2 signaling in bovine aortic ECs (BAECs). The goal of this study was to determine the mechanisms by which nanomolar resveratrol rapidly activates endothelial nitric oxide synthase (eNOS) in human umbilical vein ECs (HUVECs). We report for the first time that resveratrol increased interaction between estrogen receptor alpha (ER alpha), caveolin-1 (Cav-1) and c-Src, and increased phosphorylation of Cav-1, c-Src, and eNOS. Pretreatment with the lipid raft disruptor beta-methyl cyclodextrin or G alpha inhibitor pertussis toxin blocked resveratrol- and E(2)-induced eNOS activation and NO production. Depletion of endogenous ER alpha, not ERbeta, by siRNA attenuated resveratrol- and E(2)-induced ERK1/2, Src, and eNOS phosphorylation. Our data demonstrate that nanomolar resveratrol induces ER alpha-Cav-1-c-SRC interaction, resulting in NO production through a G alpha-protein-coupled mechanism. This study provides important new insights into mechanisms for the beneficial effects of resveratrol in ECs.
流行病学研究表明,适量饮用红酒与心血管疾病发病率降低相关。白藜芦醇是红酒中的一种多酚化合物,对啮齿动物具有心脏保护作用。尽管内皮细胞(EC)研究表明,微摩尔浓度的白藜芦醇具有多种生物学活性,但这些浓度与生理情况不相关,因为人类口服摄入后血浆中仅短暂暴露于纳摩尔水平。此前,我们报道纳摩尔浓度的白藜芦醇可激活牛主动脉内皮细胞(BAECs)中的ERK1/2信号通路。本研究的目的是确定纳摩尔浓度的白藜芦醇在人脐静脉内皮细胞(HUVECs)中快速激活内皮型一氧化氮合酶(eNOS)的机制。我们首次报道,白藜芦醇增加了雌激素受体α(ERα)与小窝蛋白-1(Cav-1)及c-Src之间的相互作用,并增加了Cav-1、c-Src和eNOS的磷酸化。用脂筏破坏剂β-甲基环糊精或Gα抑制剂百日咳毒素预处理可阻断白藜芦醇和E(2)诱导的eNOS激活及NO生成。通过siRNA耗尽内源性ERα而非ERβ,可减弱白藜芦醇和E(2)诱导的ERK1/2、Src和eNOS磷酸化。我们的数据表明,纳摩尔浓度的白藜芦醇诱导ERα-Cav-1-c-SRC相互作用,通过Gα蛋白偶联机制产生NO。本研究为白藜芦醇对内皮细胞有益作用的机制提供了重要的新见解。