Resveratrol Inhibits Rat Aortic Vascular Smooth Muscle Cell Proliferation via Estrogen Receptor Dependent Nitric Oxide Production

Abstract

Vascular smooth muscle cell (VSMC) proliferation is pivotal in the progression of hypertension, atherosclerosis, and restenosis. Resveratrol is a grape polyphenol that is implicated as an important contributor to red wine's vascular protective effects. Its antimitogenic action on VSMC is attributed to an array of pleiotropic effects, including modulation of the estrogen receptor (ER). To elucidate the mechanisms underlying resveratrol-mediated ER modulation and its inhibition of VSMC proliferation, we treated VSMC with resveratrol with or without the ER antagonist ICI 182,780 and measured cell proliferation and nitric oxide (NO) production. Resveratrol dose-dependently decreased VSMC DNA synthesis, with a half maximal inhibitory concentration (IC50) of 3.73+/-0.57 microM, and dramatically slowed cell growth, but did not induce VSMC apoptosis. Resveratrol-mediated decrease in proliferation was reversed by cotreatment with ICI 182,780, and resveratrol effectively competed with 17beta-estradiol for binding to the ER, exhibiting an IC50 of 8.92+/-0.14 microM. Resveratrol induced a sustained increase in ER-dependent NO production. Further, resveratrol-mediated decrease in VSMC proliferation was blunted by cotreatment with the general nitric oxide synthase (NOS) inhibitor N5-(1-Iminomethyl)-L-ornithine, dihydrochloride or with the inducible NOS (iNOS)-selective inhibitor S,S'-1,4-phenylene-bis (1,2-ethanediyl)bis-isothiourea, dihydrobromide, but not with the neuronal NOS-selective inhibitor 7-nitroindazole. Though resveratrol did not alter iNOS protein levels, it dose-dependently increased levels of iNOS activity, of the iNOS cofactor tetrahydrobiopterin (BH4), and of guanosine triphosphate cyclohydrolase I protein, the rate-limiting enzyme in BH4 biosynthesis. In addition, all of these effects were abolished by cotreatment with ICI 182,780. Thus, the antimitogenic effects of resveratrol on VSMC may be mediated by an ER-induced increase in iNOS activity.

Essential role of ER-α-dependent NO production in resveratrol-mediated inhibition of restenosis

“…Note that female animals were selected for these studies so as to maximize responses. However, 1) since male animals also express ERs in the vasculature (13,18), 2) since it is now recognized that ER-␣ contributes to physiological function in the male vasculature (9,27), and 3) since our prior studies in male compared with female vascular smooth muscle cells showed similar responses for Resv (14), we expect similar responses in male mice. In studies involving a pharmacological inhibition of NOS, the mice were administered N G -nitro-L-arginine methyl ester (L-NAME, 50 mg/kg) in their drinking water, starting 7 days before the denudation procedure, continuing through 14 days postdenudation.…”

“…In our prior work, we showed that Resv inhibited VSMC proliferation via an increase in NO production. These effects were abolished by a cotreatment with ER antagonist ICI-182780 (14). Recent studies also suggest that Resv binds ER-␣ and rapidly activates endothelial NOS (eNOS) nongenomically.…”

“…Resv is also a known phytoestrogen and is well established for its vascular protective effects. Recent in vitro work in our laboratory and that reported by others have suggested that Resv inhibits VSMC proliferation via the steroid hormone receptor super family of ERs (14,17,21). Furthermore, Resv induces transcriptional activity of ER-␣ and -␤ (5,17).…”

“…The vascular levels of BH4 were determined in homogenates of aortic tissues using HPLC analysis with electrochemical detection, as described previously (14).…”

Greater Effectiveness of ε-Viniferin in Red Wine Than Its Monomer Resveratrol for Inhibiting Vascular Smooth Muscle Cell Proliferation and Migration

“…[2][3][4] Epidemiological studies have also shown that red wine consumption was irreversibly correlated to a risk of coronary heart disease. 5) In practice, resveratrol inhibits the oxidation of human low-density lipoproteins, 6,7) platelet aggregation, 8) and the proliferation of vascular smooth muscle cells (VSMCs) [9][10][11][12][13][14] which can prevent the pathogenesis of atherosclerosis. Resveratrol is therefore believed to be a strong candidate for explaining the ''French paradox'' that indicates the reduction in coronary heart disease observed with red wine drinkers.…”