雌二醇对大鼠心肌缺血/再灌注损伤的干预作用及其机制

Intervention effects of estradiol on myocardial ischemia-reperfusion injury of rat and its mechanisms

目的:研究雌二醇(E2)通过雌激素受体β(ERβ)介导细胞外调节蛋白激酶(ERK)通路激活减轻心肌缺血/再灌注(I/R)损伤的作用及机制。方法:84只成年雌性SD大鼠进行去卵巢手术并随机分为:对照组、NC-siRNA腺相关病毒(AAV)组进行假手术,I/R组、E2+I/R组、NC-siRNA AAV+I/R组、NC-siRNA AAV+E2+I/R组、ERβ-siRNA AAV+E2+I/R组。采用冠状动脉左前降支结扎的方法制备心肌I/R损伤模型,E2+I/R组、NC-siRNA AAV+E2+I/R组、ERβ-siRNA AAV+E2+I/R组造模前给予E2灌胃、连续60 d,NC-siRNA AAV+I/R组、NC-siRNA AAV+E2+I/R组、ERβ-siRNA AAV+E2+I/R组造模前24 h给予相应AAV尾静脉注射。再灌注120 min后,检测血清乳酸脱氢酶(LDH)、磷酸肌酸激酶(CK)、磷酸肌酸激酶同工酶(CK-MB)含量,心肌梗死面积,心肌中ERβ、p-ERK表达水平及肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)、丙二醛(MDA)、总抗氧化力(T-AOC)的含量。结果:I/R组的血清LDH、CK、CK-MB含量、心肌梗死面积及心肌中TNF-α、IL-1β、MDA的含量均高于对照组,心肌中ERβ、p-ERK的表达水平及T-AOC的含量均低于对照组(P<0.05);E2+I/R组的血清LDH、CK、CK-MB含量、心肌梗死面积及心肌中TNF-α、IL-1β、MDA的含量均低于I/R组,心肌中ERβ、p-ERK的表达水平及T-AOC的含量均高于I/R组(P<0.05);尾静脉注射ERβ-siRNA AAV敲低ERβ的表达后,ERβ-siRNA AAV+E2+I/R组的血清LDH、CK、CK-MB含量、心肌梗死面积及心肌中TNF-α、IL-1β、MDA的含量均高于NC-siRNA AAV+E2+I/R组,心肌中ERβ、p-ERK的表达水平及T-AOC的含量均低于NC-siRNA AAV+E2+I/R组(P<0.05)。结论:雌二醇对去卵巢大鼠心肌I/R损伤具有保护作用,该作用与促进ERβ介导ERK通路激活、减轻炎症反应及氧化应激反应有关。

Objective:To study the effects of estradiol(E2)on alleviating myocardial ischemia/reperfusion(I/R)injury through estrogen receptorβ(ERβ)mediated extracellular regulated protein kinases(ERK)pathway activation.Methods:Eighty-four adult female SD rats were ovariectomized and randomly divided into control group,NC siRNA adeno-associated virus(AAV)group received sham operation,the myocardial I/R injury model was prepared by ligation of the left anterior descending coronary artery in I/R group,E2+I/R group,NC siRNA AAV+I/R group,NC siRNA AAV+E2+I/R group and ERβ-siRNA AAV+E2+I/R group.E2+I/R group,NC siRNA AAV+E2+I/R group and ERβ-siRNA AAV+E2+I/R group were treated with E20.8 mg/kg by gavage for 60 days before modeling.NC siRNA AAV+I/R group,NC siRNA AAV+E2+I/R group,and ERβ-siRNA AAV+E2+I/R group were treated with AAV by caudal vein injection 24 h before modeling.After 120 min of reperfusion,the contents of serum lactate dehydrogenase(LDH),phosphocreatine kinase(CK),phosphocreatine kinase isoenzyme(CK-MB),myocardial infarction area and the expressions of ERβ,p-ERK,the contents of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),malondialdehyde(MDA)and total antioxidant capacity(T-AOC)in myocardium were measured.Results:The contents of serum LDH,CK,CK-MB,myocardial infarction area and the contents of TNF-α,IL-1β,MDA in myocardium of I/R group were higher than those of the control group,the expression levels of ERβand p-ERK and the content of T-AOC were lower than those in the control group(P<0.05).The contents of serum LDH,CK and CK-MB,myocardial infarction area and the contents of TNF-α,IL-1βand MDA in myocardium of E2+I/R group were lower than those of the I/R group,the expression levels of ERβand p-ERK and the content of T-AOC were higher than those of the I/R group(P<0.05).After knockdown ERβby caudal vein injection of ERβ-siRNA AAV,the contents of serum LDH,CK and CK-MB,myocardial infarction area and the contents of TNF-α,IL-1βand MDA in myocardium of ERβ-siRNA AAV+E2+I/R group were higher than those of NC-siRNA AAV+E2+I/R,the expression levels of ERβand p-ERK and the content of T-AOC were lower than those of NC-siRNA AAV+E2+I/R(P<0.05).Conclusion:E2 has protective effects on myocardial I/R injury in ovariectomized rats,which are related to the promotion of ERβmediating the activation of ERK pathway,reducing inflammatory and oxidative stress responses.