Curcumin inhibits the apoptosis ofHUVECs induced by oxidized low density lipoprotein / 基础医学与临床

ABSTRACT

Objective To investigate the protective effect of curcumin on apoptosis of human umbilical vein endothelial cells (HUVECs) induced by oxidized low density lipoprotein (ox-LDL) and its possible mechanism.Methods Cultivated HUVECs were divided into six groups: control group, ox-LDL group, ox-LDL plus endoplasmic reticulum stress(ERS) inhibitor PBA group,curcumin group, ox-LDL plus curcumin group,ox-LDL plus curcumin plus PI3K inhibitor LY294002 group.Cell viabilities were evaluated by CCK-8 assays.The proportions of apoptotic cells were assessed by flow cytometry.The translocation of activating transcription factor 6 (ATF6) observed by laser confocal microscopy.Western blot was used to determine the expression of the ERS associated proteins:glucose-regulated protein 78(GRP78), protein kinase-like ER kinase(PERK), inositol-requiring kinase1(IRE-1) and the related pathways protein: LOX-1, AKT and phophorylated AKT.Results Compared with control group,increasedthe proportions of apoptotic cells(P<0.01),enhanced the expressions of ERS related proteins(P<0.01),promoted the transfer of ATF6 into the nucleus,as well as increased the expression of LOX-1(P<0.01)and decreased the expression of p-AKT(P<0.01) in the ox-LDL group;Compared with ox-LDL group,PBA inhibited ox-LDL-induced HUVECs apoptosis(P<0.01),curcumin inhibited ox-LDL-induced the expression of ERS associated protein and LOX-1(P<0.01), the nuclear translocation of ATF6, the apoptosis of HUVECs (P<0.01), and it also increased ox-LDL-induced down-regulation of p-AKT expression (P<0.01);LY294002 partially attenuated the inhibitory effect of curcumin on ERstress-related protein expression induced by ox-LDL(P<0.05).ConclusionsCurcumin can reduce ox-LDL induced apoptosis of HUVECs, its mechanism may be through the inhibition of LOX-1 expression and activation of AKT pathway to reduce ERS in cell.