Different short- and long-term effects of resveratrol on nuclear factor-κB phosphorylation and nuclear appearance in human endothelial cells

Background: Resveratrol (a naturally occurring phytoalexin found in grapes and wine) has cardiovascular protective effects that suggest the antiatherogenic (ie, antiinflammatory) activities of the compound on endothelial cells. Objective: The antiinflammatory activity of resveratrol could be mediated by its interference with nuclear factor-κB (NF-κB)–dependent transcription. Thus, we studied the in vitro influence of physiologic concentrations of resveratrol (≤ 1 μmol/L) on the NF-κB signaling pathway after tumor necrosis factor α (TNF-α) stimulation of endothelial cells. Design: The effects of a 30-min (acute) and an overnight incubation of resveratrol on the nuclear appearance of p50-NF-κB and p65-NF-κB on serine and tyrosine phosphorylation of the inhibitory subunit κB α (IκBα), cytoplasmic concentrations of IκBα, NF-κB phosphorylation or nitrosylation, the reduction of the mitotic inhibitor p21, and the activation of peroxisome proliferator–activated receptor α were evaluated. Results: The nuclear appearance of p50-NFκB and p65-NFκB acutely induced by TNF-α was not modified by resveratrol but was increased after overnight incubation with resveratrol alone or in combination with TNF-α. Acute treatment with resveratrol did not modify TNF-α–induced cytoplasmic IκBα serine phosphorylation but did increase IκBα tyrosine phyophorylation. Resveratrol increased the tyrosine phosphorylation (but not nitrosylation) of immunoprecipitated NF-κB, did not decrease cellular p21, and did not increase peroxisome proliferator–activated receptor α activity. Conclusions: Acute resveratrol treatment does not inhibit the nuclear appearance of NF-κB in human umbilical vein endothelial cells, but overnight treatment does. The increase in tyrosine phosphorylation of IκBα, p50-NF-κB, and p65-NF-κB suggests the involvement of such alterations in the modulation of NF-κB transcription activity.