Statins prevent NF-kappaB transactivation independently of the IKK-pathway in human endothelial cells.

Statins have been linked to a wide range of vascular benefits, many of them are likely to be due to attenuation of chronic vascular inflammation. Nuclear factor kappaB (NF-kappaB) is one of the key regulators of transcription of a variety of genes involved in immune and inflammatory responses. Therefore, we investigated the effect of statins on TNF-alpha-induced NF-kappaB signaling in human endothelial cells (EC). ECs were pre-incubated for 16 h with cerivastatin (10(-9) to 10(-7) M) or vehicle in the presence or absence of mevalonate, followed by stimulation with 20 ng/ml TNF-alpha. Statin-treatment prevented TNF-alpha-induced NF-kappaB binding activity, nuclear translocation of the NF-kappaB p65 subunit, as well as NF-kappaB controlled tissue factor (TF) gene transcription in cultured EC. IkappaBalpha phosphorylation and IkappaBalpha degradation, however, still occurred in statin-treated cells. TNF-alpha also activated phosphatidylinositol (PI)3-kinase, as reflected by phosphorylation of Akt. Statin treatment of cells abrogated TNF-alpha-induced Akt phosphorylation and p65 nuclear translocation. As observed with statins, inhibition of PI3-kinase activity by Ly294002 also blocked TNF-alpha-induced p65 translocation, but did not prevent IkappaBalpha phosphorylation nor IkappaBalpha degradation. These studies demonstrate that TNF-alpha-induced NF-kappaB activation is abrogated by statin treatment in HUVEC independently of the classical IKK-pathway but via inhibition of PI3-kinase/Akt signaling.