Valsartan inhibits angiotensin Ⅱ-induced vascular smooth muscle cell apoptosis / 中华急诊医学杂志

ABSTRACT

Objective To investigate the impacts of valsartan on cell apoptosis induced by angiotensin Ⅱ in vascular smooth muscle cells,and discuss whether the mechanism is relevant to AMP-Activated Protein Kinases.Methods Vascular smooth muscle cells (A7r5) were designated to 5 groups①control (DMSO) group,②Angiotensin Ⅱ (Ang]Ⅱ) 100 μmo]/L group,③Angiotensin lⅡ 100 μmol/ L + valsartan 10 μmol/L group,④Angiotensin Ⅱ 100 μmol/L + valsartan 10 μmol/L + compound C 1 μmol/L group,⑤ Angiotensin Ⅱ 100 μmol/L + 5-Aminoimidazole-4earboxamide-ribo-nucle-oside (AICAR) 100 μmol/L group,after 24h incubation,the intracellular activity of Caspase 3 was measured by spectrophotometry,the cell apoptosis were enumerated by low cytometry,the intracellular AMP-Activated Protein Kinases (AMPK) phosphorylation and total expression quantity were examined by western blot,the intracellular reactive oxygen species (ROS) was measured by fluorescent probe DCFH-DA,the intracellular activity of total superoxide dismutase (SOD) was measured by WST-1 method,the intracellular activity of Malondialdehyde (MDA) was measured by TBA method.Two groups were compared by using Student t test.Differences among multiple groups were evaluated by ANOVA.Results Compared with control group,the cell apoptosis of Angiotensin Ⅱ group was increased [(45.46 ± 15.40)％ vs.(1.88 ± 3.28)％,P =0.002],the synthesis of ROS was increased [(9.24 ±0.46) vs.(1.00 ±0.00),P＜0.01],theactivity of Caspase 3 was increased [(35.03 ± 3.54) vs.(13.33 ± 1.79),P ＜ 0.01],the activity of MDA was increased [(4.32 ±0.73) vs.(2.05 ±0.18),P＜0.01)],the phosphorylation of AMPK was decreased,the activity of SOD was decreased [(90.29 ± 14.73) vs.(136.02 ± 18.82),P =0.001];compared with Angiotensin Ⅱ group,the cell apoptosis of Angiotensin Ⅱ + valsartan group and Angiotensin Ⅱ + AICAR group were decreased [(24.91 ±8.46)％ vs.(45.46±15.40)％,P=0.031];[(27.90 ±4.39)％ vs.(45.46 ± 15.40)％,P =0.038],the synthesis of ROS was decreased [(2.37 ±0.05) vs.(9.24±0.46),P＜0.01];[(2.79±0.31) vs.(9.24±0.46),P＜0.01],the activity of Caspase3wasdecreased [(18.08±2.69) vs.(35.03±3.54),P＜0.01];[(27.83±3.56) vs.(35.03 ± 3.54),P =0.002],the activity of MDA were decreased [(3.25 ± 0.55) vs.(4.32 ± 0.73),P=0.017];[(3.46±0.60) vs.(4.32±0.73),P=0.047],the phosphorylationofAMPKwas increased,the activity of SOD was increased [(140.71 ±20.27) vs.(90.29 ± 14.73),P ＜0.01];[(116.73 ± 17.96) vs.(90.29 ± 14.73),P =0.029];compared with Angiotensin Ⅱ + valsarntan group,the cell apoptosis of Angiotensin Ⅱ + valsartan + compound C group was increased [(43.84 ± 12.00) ％ vs.(24.91 ± 8.46)％,P =0.043],the synthesis of ROS was increased [(4.64 ± 0.15) vs.(2.37 ± 0.05),P ＜ 0.01],the activity of Caspase 3 was increased [(25.64 ± 3.52) vs.(18.08 ± 2.69),P=0.011],the activity of MDA was increased [(5.12 ±0.92) vs.(3.25 ±0.55),P＜ 0.01],the phosphorylation of AMPK was decreased,the activity of SOD was decreased [(99.48 ± 16.59) vs.(90.29 ± 14.73),P =0.002)].Conclusions Valsartan could inhibit angiotensin Ⅱ-induced vascular smooth muscle cell apoptosis via activating AMPK,suppressing the synthesis of ROS and the activity of MDA,elevating the activity of SOD.