HIF-1α/BNIP3信号通路在七氟烷减轻大鼠心肌缺血再灌注损伤中的作用:与自噬的关系

Role of HIF-1α/BNIP3 signaling pathway in sevoflurane-induced attenuation of myocardial ischemia-reperfusion injury in rats:relationship with autophagy

目的评价低氧诱导因子-1α(HIF-1α)/Bcl-2/E1B-19kDa相互作用蛋白3(BNIP3)信号通路在七氟烷减轻大鼠心肌缺血再灌注损伤中的作用及其与自噬的关系。方法SPF级健康成年雄性SD大鼠90只,体重300~350 g,采用随机数字表法分为5组(n=18):假手术组(Sham组)、心肌缺血再灌注组(I/R组)、七氟烷组(SEV组)、HIF-1α抑制剂2ME2组(2ME2组)和2ME2+七氟烷组(MSP组)。采用结扎冠状动脉左前降支40 min再灌注120 min的方法建立大鼠心肌缺血再灌注损伤模型。SEV组于再灌注即刻吸入2.4%七氟烷15 min;2ME2组和MSP组在结扎冠状动脉左前降支前1 h时腹腔注射2ME215 mg/kg,其余处理同I/R组或SEV组。于再灌注120 min时处死大鼠取左室心肌组织,采用Western blot法检测HIF-1α和BNIP3表达;电镜下观察自噬小体;DHE法检测ROS活性;TTC法确定心肌梗死面积。结果与Sham组比较,其余4组心肌ROS活性、自噬小体数目和心肌梗死面积增加,I/R组和SEV组HIF-1α和BNIP3表达上调(P<0.05);与I/R组比较,SEV组心肌ROS活性、自噬小体数目和心肌梗死面积减少,HIF-1α和BNIP3表达上调(P<0.05),2ME2组和MSP组心肌ROS活性、自噬小体数目和心肌梗死面积差异无统计学意义(P>0.05),HIF-1α和BNIP3表达下调(P<0.05);与SEV组比较,2ME2组和MSP组心肌ROS活性、自噬小体数目和心肌梗死面积增加,HIF-1α和BNIP3表达下调(P<0.05)。结论HIF-1α/BNIP3信号通路参与了七氟烷减轻大鼠心肌缺血再灌注损伤的过程,与抑制自噬有关。

Objective To evaluate the role of hypoxia-inducible factor-1α(HIF-1α)/Bcl-2/E1B-19kDa interacting protein 3(BNIP3)signaling pathway in sevoflurane-induced attenuation of myocardial ischemia-reperfusion(I/R)injury in rats and the relationship with autophagy.Methods Ninety healthy adult male Sprague-Dawley rats,weighing 300-350 g,were randomly divided into 5 groups(n=18 each):sham operation group(Sham group),I/R group,sevoflurane group(SEV group),HIF-1a inhibitor 2ME2 group(2ME2 group),and 2ME2+sevoflurane group(MSP group).Myocardial I/R injury model was established by ligating the left anterior descending branch of coronary artery for 40 min followed by 120-min reperfusion in anesthetized rats.In SEV group,2.4%sevoflurane was inhaled for 15 min starting from the beginning of reperfusion.In 2ME2 group and MSP group,2ME2(15 mg/kg)was intraperitoneally injected at 1 h before ligation of the left anterior descending branch of coronary artery,and the other treatments were similar to those previously described in group I/R or in group SEV.Animals were sacrificed at 120 min of reperfusion,and the left ventricular myocardium was taken for determination of the expression of HIF-1αand BNIP3(by Western blot),activity of ROS(by DHE),and myocardial infarct size(by TTC)and for observation of autophagosome(with an electron microscope).Results Compared with Sham group,the activity of ROS,the number of autophagosome and myocardial infarct size were significantly increased in the other four groups,the expression of HIF-1αand BNIP3 was up-regulated in I/R group and SEV group(P<0.05).Compared with I/R group,the activity of ROS,the number of autophagosome and myocardial infarct size were significantly decreased in the other four groups,the expression of HIF-1αand BNIP3 was up-regulated in SEV group,and no significant difference was found in the activity of ROS,the number of autophagosome or myocardial infarct size(P>0.05),and the expression of HIF-1αand BNIP3 was down-regulated in 2ME2 and MSP groups(P<0.05).Compared with SEV group,the activity of ROS,the number of autophagosome and myocardial infarct size were significantly increased,and the expression of HIF-1αand BNIP3 was down-regulated in 2ME2 and MSP groups(P<0.05).Conclusion HIF-1α/BNIP3 signaling pathway is involved in sevoflurane-induced attenuation of myocardial I/R injury,which is related to inhibiting autophagy in rats.