Intracellular ROS generation detection in vitro by DCFH-DA staining. The upper panel shows fluorescence microscopic images of cultured cardiomyocytes exposed to whether normal- glucose concentration or high- glucose concentration. As shown in the upper panel, ROS level are detected in wild type, PERK dn, ATF6 dn and IRE1 dn cardiomyocytes. The lower panel shows the fluorescent intensity (left side) and relative fluorescent intensity (right side) of DCFH-DA staining in wild type, PERK dn, ATF6 dn and IRE1 dn cardiomyocytes. Values in this figure are presented by columns in (mean ± SD) manner.