Resveratrol down-regulates endothelin type B receptors in vascular smooth muscle cells via Sirt1/ERK1/2/NF-кB signaling pathways.

Silent information regulator family protein 1 (Sirt1) has gained attention for protective effects against cardiovasc diseases. Vascular smooth muscle endothelin type B (ETB) receptors are related to the pathogenesis of cardiovascular diseases. Elevated oxidized low-density lipoprotein (ox-LDL) is associated with atherosclerosis. This study will investigate whether resveratrol (a Sirt1 activator, Res) is involved in oxidized low density lipoprotein (ox-LDL)-mediated- regulation of ETB receptors in rat superior mesenteric arteries (SMA). The rat SMA segments were cultured in the presence and absence of ox-LDL with or without Res and specific inhibitor (U0126) for the extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) for 24 h. After organ culture, the contractile responses to sarafotoxin 6c (S6c) were studied using a sensitive myograph, and the ETB receptor protein expression was detected using Western blotting. The results showed that Res concentration-dependently suppressed the ox-LDL -induced up-regulation of ETB receptors expression and receptor-mediated vasoconstriction. In addition, these effects could be inhibited by U0126. Furthermore, activity of ERK1/2 phosphorylation and P65 acetylation induced by ox-LDL were blocked by Res. In conclusion, Res down-regulated ETB receptors through up-regulating Sirt1 and followed by ERK1/2/NF-кB signaling pathways in the organ culture SMA.