Combination effects of cigarette smoke extract and ambient ultrafine particles on endothelial cells

► We determined ROS, MAPKs activation, and Egr-1 and IL-6 upregulation in endothelial cells with exposure to UFPs and/or CSE. ► ROS generation in cells exposed to UFPs and/or CSE activated MAPKs induced Egr-1 upregulation and IL-6 generation. ► Coexposure to UFPs with CSE greatly enhanced these effects, resulting in endothelial inflammation and dysfunction.