The inhibition in tumor necrosis factor-alpha-induced attenuation in endothelial thrombomodulin expression by carvedilol is mediated by nuclear factor-kappa B and reactive oxygen species

Carvedilol, a nonselective beta-adrenoceptor antagonist, has been shown to possess antioxidant effects and reduce the risk of hospitalization and death in patients with severe congestive heart failure, which is featured by the activation of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha), and leads to thrombotic complications. Thrombomodulin (TM) plays protective roles against thrombosis. Treatment of ECs with TNF-alpha resulted in a down-regulation in the TM expression in a time-dependent manner. Pre-treatment of ECs with carvedilol (1 and 10 mu M) for 1 h significantly up-regulated the TM expression in ECs in response to TNF-alpha. When ECs were pre-treated with a nuclear factor-kappa B (NF-kappa B) inhibitor, i.e., parthenolide, their TNF-alpha-mediated down-regulation of TM expression was inhibited. Pre-treatment of ECs with carvedilol inhibited the NF-kappa B-DNA binding activity in ECs induced by TNF-alpha. Our findings provide insights into the mechanisms by which carvedilol exerts anti-thrombotic effects by inducing TM expression in ECs in response to pro-inflammatory stimulation.