Keap-1/Nrf2/HO-1通路在曲美他嗪抑制顺铂诱导大鼠心肌损伤作用的研究

Effect of Keap-1/Nrf2/HO-1 pathway on inhibition of cisplatin induced myocardial injury in rats by trimetazidine

目的:研究曲美他嗪(trimetazidine,TMZ)减轻顺铂(cisplatin)诱导的大鼠心肌细胞损伤,并通过抑制Keap-1调控Nrf2/HO-1起到心脏保护作用。方法:分离大鼠心肌细胞,分成三组,对照组、顺铂处理组(200μM)和顺铂(200μM)+TMZ(200μM)处理组。检查细胞活力和ROS的含量,Western blot及Real-time PCR方法检测Nrf2及其上游Keap-1和下游HO-1的表达。结果:TMZ明显减轻顺铂对心肌细胞活力的抑制(P<0.01)。TMZ预处理均能有效地抑制活性氧物质ROS(P<0.01)的水平。Western blot结果显示,TMZ预处理可明显降低Nrf2的表达(P<0.01),抑制Keap-1的蛋白表达(P<0.01),增强抗氧化酶类靶蛋白如血红素氧合酶1(hemo oxygenase 1,HO-1)的蛋白表达水平(P<0.01)。Real-time PCR结果显示,与对照组相比,顺铂处理的Nrf2表达显著增加(P<0.0001),TMZ预处理明显促进了Nrf2的核易位(P<0.01);顺铂显著促进Keap-1(P<0.0001)和HO-1的表达(P<0.0001),TMZ进行预处理可显著抑制Keap-1的表达(P<0.0001),显著增强HO-1的表达水平(P<0.001)。结论:TMZ抑制了顺铂引起的心脏损伤,部分依赖于Keap-1/Nrf2/HO-1信号通路的抗氧化防御作用,显示出TMZ具有心脏保护作用,可作为抗氧化剂治疗化疗药物引起的心脏损伤。

Objective:To study the effect of trimetazidine(TMZ)in reducing rat myocardial injury induced by cisplatin and the cardioprotective effect of Nrf2/HO-1 by inhibiting Keap-1.Methods:Rat myocardial cells were isolated and divided into three groups:control group,cisplatin treated group(200μM),and cisplatin+TMZ(200μM)treated group.Cell viability and production of reactive oxygen species(ROS)were examined.Western blot and Real-time PCR were used to detect the expression of Nrf2,its upstream Keap-1,and downstream HO-1.Results:TMZ reduced the inhibitory effect of cisplatin on cardiomyocyte activity(P<0.01).TMZ pretreatment could effectively inhibit ROS production(P<0.01).Western blot results showed that TMZ pretreatment increased the expression of Nrf2(P<0.01),inhibited the expression of Keap-1(P<0.01),and enhanced HO-1 expression level(P<0.01).Compared with the control group,Real-time PCR revealed that the expression of Nrf2 was significantly increased by cisplatin treatment(P<0.0001),and TMZ pretreatment promoted the nuclear translocation of Nrf2(P<0.01).Cisplatin significantly promoted the expression of Keap-1(P<0.0001)and hemo oxygenase 1(HO-1)(P<0.0001).TMZ pretreatment significantly inhibited the expression of Keap-1(P<0.0001)and significantly enhanced the expression of HO-1(P<0.001).Conclusions:TMZ significantly inhibited the myocardial injury induced by cisplatin,in part owing to the Keap-1/Nrf2/HO-1 associated antioxidant defense system.The findings suggest that TMZ has a cardioprotective effect as an antioxidant for the treatment of myocardial injury induced by chemotherapeutic drugs.