延胡索乙素改善PDGF-BB诱导的VSMCs氧化应激损伤的机制

Mechanism of tetrahydropalmatine inhibiting oxidative stress damage of VSMCs induced by PDGF-BB

目的研究延胡索乙素(Thp)对血小板衍生生长因子-BB(PDGF-BB)诱导的大鼠主动脉血管平滑肌细胞(VSMCs)氧化应激损伤的保护作用,并基于核因子红系2相关因子2(Nrf2)/血红素加氧酶1(HO-1)信号通路探究其可能机制。方法在Thp抑制PDGF-BB诱导的VSMCs氧化应激损伤效应研究中,将VSMCs分为对照组、PDGF-BB组(25 ng/mL)及Thp低、中、高浓度组(5、10、20 mg/mL)。在Thp作用机制研究(沉默Nrf2)中,将VSMCs分为PDGF-BB+阴性对照siRNA(NC-siNrf2)组(25 ng/mL PDGFBB+NC-siNrf2),PDGF-BB+Thp+NC-siNrf2组(25 ng/mL PDGF-BB+10 mg/mL Thp+NC-siNrf2),PDGF-BB+Nrf2小干扰RNA(siNrf2)组(25 ng/mL PDGF-BB+siNrf2),PDGF-BB+Thp+siNrf2组(25 ng/mL PDGF-BB+10.0 mg/mL Thp+siNrf2)。2个实验均检测VSMCs的增殖、迁移能力,活性氧(ROS)水平,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性以及Nrf2和HO-1蛋白表达。结果与对照组比较,PDGF-BB组VSMCs的增殖、迁移能力显著增强(P<0.01),ROS水平显著升高(P<0.01),SOD、CAT活性及Nrf2、HO-1蛋白的相对表达量均显著降低(P<0.01);与PDGF-BB组比较,Thp不同浓度组VSMCs的增殖、迁移能力均显著下降(P<0.01),ROS水平均显著降低(P<0.01),SOD、CAT活性及Nrf2、HO-1蛋白的相对表达量均显著升高(P<0.01)。沉默Nrf2可显著逆转Thp对PDGF-BB诱导VSMCs氧化应激损伤的改善作用(P<0.01)。结论Thp可以通过激活Nrf2介导的抗氧化防御途径来降低VSMCs的氧化应激水平,从而抑制VSMCs的增殖、迁移。

OBJECTIVE To study the protective effect of tetrahydropalmatine(Thp)on platelet-derived growth factor-BB(PDGF-BB)induced oxidative stress injury in vascular smooth muscle cells(VSMCs)of rats,and to explore its possible mechanism based on the nuclear factor-erythroid 2-related factor 2(Nrf2)/heme oxygenase(HO-1)signaling pathway.METHODS In the study about Thp inhibiting PDGF-BB-induced oxidative stress injury in VSMCs,VSMCs were divided into control group,PDGF-BB group(25 ng/mL),and Thp low-concentration,medium-concentration and high-concentration groups(5,10,20 mg/mL).In the Thp mechanism experiment(silencing Nrf2),VSMCs were divided into PDGF-BB+negative control of siRNA(NC-siNrf2)group(25 ng/mL PDGF-BB+NC-siNrf2),PDGF-BB+Thp+NC-siNrf2 group(25 ng/mL PDGF-BB+10 mg/mL Thp+NC-siNrf2),PDGF-BB+Nrf2 small interfering RNA(siNrf2)group(25 ng/mL PDGF-BB+siNrf2)and PDGF-BB+Thp+siNrf2 group(25 ng/mL PDGF-BB+10.0 mg/mL Thp+siNrf2).The proliferative and migratory capabilities of VSMCs,the level of reactive oxygen species(ROS),the activities of superoxide dismutase(SOD)and catalase(CAT)as well as the protein expressions of Nrf2 and HO-1 in VSMCs were all detected in two experiments.RESULTS Compared with the control group,the proliferative and migratory capabilities of VSMCs in the PDGF-BB group were significantly enhanced(P<0.01),and the level of ROS significantly increased(P<0.01),while the activities of SOD and CAT,and the relative expressions of Nrf2 and HO-1 protein significantly decreased(P<0.01).Compared with the PDGF-BB group,the proliferative and migratory capabilities of VSMCs in the Thp groups at different concentrations were significantly reduced(P<0.01),the levels of ROS were significantly reduced,while the activities of SOD and CAT,and relative expressions of Nrf2 and HO-1 were significantly enhanced(P<0.01).Silencing Nrf2 significantly reversed the improvement of Thp on the oxidative stress damage of VSMCs induced by PDGF-BB(P<0.01).CONCLUSIONS Thp can reduce the oxidative stress level of VSMCs by activating the Nrf2-mediated antioxidant defense pathway,thereby inhibiting the proliferation and migration of VSMCs.