Abstract: Objective To investigate the effect of lncRNA TUG1 on oxidative damage induced by ox-LDL in vascular endothelial cells（HUVEC）.Methods HUVEC was divided into four groups: control group, ox-LDL group (100g/mL ox-LDL treatment), si-NC+ intervention group (negative control of transfected siRNA), si-TUG1 + intervention group (transfected TUG1 siRNA).The expression of TUG1 in vascular endothelial cells before and after ox-LDL treatment was detected by Realtime PCR. TUG1 siRNA and siRNA negative controls were transfected into vascular endothelial cells, Realtime PCR was used to detect the expression of TUG1 in vascular endothelial cells under ox-LDL. The level of ROS in the cells was detected by DCFH-DA, WST assay was used to detect the activity of SOD in cells, the content of MDA in culture medium was detected by TBA colorimetry, the activity of LDH in culture medium was detected by LD-P, NO content in the culture medium was measured by nitrate reductase, flow cytometry was used to detect the changes of cell apoptosis, Western blot was used to detect the level of c-caspase-3 protein in cells. Results The expression level of TUG1 in ox-LDL group increased compared with control group（P<0.05）.Transfection of TUG1 siRNA could reduce the expression of TUG1 in vascular endothelial cells under ox-LDL condition （P<0.05）.siRNA negative control had no effect on TUG1 expression in cells. The level of ROS in ox-LDL group cells increased（P<0.05）, the activity of SOD reduced（P<0.05）, the content of MDA in the culture medium increased（P<0.05）, the activity of LDH elevated（P<0.05）, the content of NO reduced（P<0.05）, the rate of apoptosis increased（P<0.05）, the level of c-caspase-3 protein in the cells increased（P<0.05）.The si-TUG1 + intervention group significantly alleviated the above changes in ox-LDL group (P<0.05).. Conclusions Knockout of lncRNA TUG1 alleviates ox-LDL induced oxidative damage in vascular endothelial cells,decrease the apoptosis of vascular endothelial cells.

Key words: vascular endothelial cells, ox-LDL, lncRNA TUG1, oxidative damage