Effect and mechanism of artemisinin on alleviating vascular endothelial cell injury induced by oxidized low density lipoprotein

Objective　To investigate the effects of artemisinin (ART) on vascular endothelial cell injury induced by oxidized low density lipoprotein (ox-LDL), and explore its potential molecule mechanism. Methods　The human umbilical vein endothelial cells EA.hy926 in logarithmic phase were treated respectively with 0, 50, 100, 150 and 200 mg/ml of ox-LDL and 0, 1, 5, 10 and 20 mmol/L of ART. The cell viability were detected by MTT assay. To detected the effect of ART on cells, the EA.hy926 cells were divided into control group (without any treatment), ox-LDL group (treated with 100 mg/ml ox-LDL), ox-LDL+ART group (treated with 100 mg/ml ox-LDL and 10 mmol/L ART) and ox-LDL+ART+3-methyladenine (3-MA) group (treated with 100 mg/ml ox-LDL, 10 mmol/L ART and 5 mmol/L 3-MA). To detected the effect of transient receptor potential channel vanillic acid receptor subtype Ⅳ (TRPV4) on the cells, the EA.hy926 cells were divided into control group, ox-LDL group, ox-LDL+ART group and ox-LDL+ART+ruthenium red (RR) group (treated with 100 mg/ml ox-LDL, 10 mmol/L ART and 10 mmol/L RR). The cell viability were detected by MTT assay. The expressions of TRPV4, autophagy associated proteins (LC3-Ⅱ/LC3-Ⅰ and p62) and apoptosis associated protein (Bcl-2, Bax) were detected by Western blotting. Cell apoptosis were detected by flow cytometry. Results　The cell viability of EA.hy926 decreased with the increase of ox-LDL concentration. The viability of ox-LDL induced cells was significantly upregulated by ART (P<0.05). Compared with the control group, the viability of cells, and the expression levels of p62, Bcl-2 and TRPV4 decreased significantly in the ox-LDL group (P<0.05), but the LC3-Ⅱ/LC3-Ⅰ ratio, cell apoptosis rate and expression level of Bax was significantly up-regulated in ox-LDL group (P<0.05). Compared with the ox-LDL group, the cell viability, LC3-Ⅱ/LC3-Ⅰ ratio, the protein expression levels of Bcl-2 and TRPV4 increased significantly, but the cell apoptosis rate, protein expression levels of p62 and Bax decreased significantly in ox-LDL+ART group (P<0.05). Compared with the ox-LDL+ART group, the cell viability, LC3-Ⅱ/LC3-Ⅰ ratio, and protein expression level of Bcl-2 decreased significantly (P<0.05), but the cell apoptosis rate, protein expression levels of p62 and Bax were up-regulated significantly in ox-LDL+ART+3-MA group and ox-LDL+ART+RR group (P<0.05). Conclusion　ART can promote autophagy by activating TRPV4 to reduce ox-LDL induced vascular endothelial cell injury. DOI: 10.11855/j.issn.0577-7402.2021.04.03