Side chain carbon losssalidroside analogues (N04) protects EAhy926 human endothelial cells against hypoxia injury by regulating the expressions of HIF-1α-related factors / 医学研究生学报

ABSTRACT

Objective Salidroside is a major active component of integripetal rhodiola herbal medicine, which has a significant activity against hypoxia and ischemia.This study was to investigate the effects of side chain carbon losssalidroside analogues (N04) on the expressions of HIF-1α-related factors in the hypoxia-injured EAhy926 human vascular endothelial cells.Methods EAhy926 human umbilical vein endothelial cells in the logarithmic growth phase were randomly divided into a normal control, a hypoxia model control, a salidroside, a high-dose N04, a medium-dose N04, and a low-dose N04 group.The hypoxia model was established by depriving the culture medium of sugar and serum and culturing the EAhy926 cells in an environment of 95%N2+5%CO2 for 2 hours, followed by intervention with salidroside at 1×10-6 mol/L and N04 at 1×10-6, 1×10-7, and 1×10-8 mol/L, respectively.Then, the activity of the cells was detected by MTT assay, their LDH activity examined by spectrophotometry, the mRNA expressions of HIF-1α and VEGF measured by RT-PCR, the protein expressions of HIF-1α, VEGF and pVHL determined by Western blot, and the activity of eNOS measured by ELISA.Results Compared with the normal control group, the hypoxia model cells showed significantly reduced activity (0.51±0.05 vs 0.27±0.02, P<0.01), an elevated LDH level ([6.65±1.43] vs [78.82±2.33] U/L, P<0.01), and decreased eNOS activity ([1.56±0.23] vs [1.16±0.20] U/100 mL, P<0.01).In comparison with the hypoxia model group, the cells treated with high-, medium-, and low-dose N04 exhibited remarkably increased activity (0.27±0.02 vs 0.0.42±0.05, 0.40±0.03 and 0.37±0.04, P<0.01), a reduced LDH level ([78.82±2.33] vs [53.05±3.90], [58.42±4.45] and [62.73±3.63] U/L, P<0.01), and increased eNOS activity ([1.16±0.20] vs [3.01±0.47], [2.60±0.26] and [2.32±0.29] U/100 mL, P<0.01).The activity of eNOS was also increased in the salidroside group ([2.32±0.29] U/100 mL, P<0.01).The cell activity in the high-and medium-dose N04 groups was markedly higher than that in the salidroside group (P<0.05), and so was the eNOS activity in the high-dose N04 group and the LDH level in the medium-and low-dose N04 groups (P<0.05).In comparison with the normal control group, the expressions of HIF-1α mRNA, HIF-1α protein and VEGF protein were significantly up-regulated in the hypoxia model group (P<0.01) while that of the pVHL protein markedly down-regulated (P<0.01).Compared with the hypoxia model group, the expressions of HIF-1α mRNA, HIF-1α protein and VEGF protein were remarkably reduced (P<0.05), while that of the pVHL protein markedly elevated (P<0.05).Both the expressions of VEGF mRNA and HIF-1α protein were significantly lower in the medium-and low-dose N04 groups than in the salidroside group (P<0.05).Conclusion N04 can protect vascular endothelial cells against hypoxia-induced injury by regulating the expression of HIF-1α-related factors and eNOS.