Effects of ox-LDL on HUVECs injury and circ_0003204 expression. (a) HUVECs were treated with 50, 100, and 200 μg/mL ox-LDL for 24 h, and the viability of HUVECs was measured by CCK8 assay. (b) HUVECs were treated with 100 μg/mL ox-LDL for 12, 24, and 48 h, respectively. CCK8 assay was used to detect the viability of HUVECs. (c–k) HUVECs were treated with 100 μg/mL ox-LDL for 24 h. (c) The apoptosis of HUVECs was assessed by flow cytometry. (d) The activity of caspase-3 was determined using Caspase-3 Activity Assay Kit. (e–g) The contents of IL-6, IL-1β, and TNF-α were tested via the IL-6, IL-1β, and TNF-α ELISA Assay Kits, respectively. (h–j) The expression of ROS and MDA and the activity of LDH were measured using the ROS, MDA, and LDH Assay Kits, respectively. (k) The expression of circ_0003204 was determined by qPCR. *P < 0.05.