淫羊藿次苷Ⅱ通过沉默信息调控子1-叉头蛋白O1通路减轻心肌缺血再灌注损伤

Icariside Ⅱ reduces myocardial ischemia-reperfusion injury through activating silent information regulator 1/acetylated-forkhead box O1 pathway

目的探究淫羊藿次苷Ⅱ(ICSⅡ)预处理对心肌缺血再灌注损伤大鼠的保护作用,初步探究可能的作用机制。方法将大鼠分为假手术组、模型组、淫羊藿次苷Ⅱ(ICSⅡ)组、沉默信息调控子1(SIRT1)抑制剂(Selisistat)组、ICSⅡ+Selisistat组;各组大鼠预处理后采用左冠状动脉前降支结扎法建立心肌缺血再灌注损伤模型大鼠。超声检测大鼠心室功能变化;HE染色观察大鼠心肌组织病理学变化情况;酶联免疫吸附法检测血清白细胞介素1β(IL-1β)、心肌肌钙蛋白I(cTnI)和肿瘤坏死因子α(TNF-α)水平;Tunel染色法检测心肌组织凋亡;免疫印迹法检测心肌组织中SIRT1、乙酰化叉头蛋白O1(Ac-FOXO1)、Bcl-2相关X蛋白(Bax)、天冬氨酸特异性半胱氨酸蛋白酶3(Caspase-3)、Cleaved-Caspase-3、B淋巴细胞瘤2(Bcl-2)蛋白表达情况。结果与假手术组相比,模型组左心室舒张末压(LVEDP)升高,平均动脉压(MAP)、左心室收缩压(LVSP)、左心室射血分数(LVEF)、左心室短轴缩短率(LVFS)降低,cTnI、TNF-α、IL-1β水平升高,细胞凋亡率升高,SIRT1表达降低,Ac-FOXO1表达升高,心肌组织Bax、Cleaved-Caspase-3蛋白表达升高,Bcl-2蛋白表达降低(均P<0.05)。与模型组相比,ICSⅡ组LVEDP降低,MAP、LVSP、LVEF、LVFS升高,cTnI、TNF-α、IL-1β水平降低,细胞凋亡率降低,SIRT1表达升高,Ac-FOXO1表达降低,心肌组织Bax、Cleaved-Caspase-3蛋白表达降低,Bcl-2蛋白表达升高(均P<0.05);Selisistat组LVEDP升高,MAP、LVSP、LVEF降低,cTnI、TNF-α、IL-1β水平升高,细胞凋亡率升高,SIRT1表达降低,Ac-FOXO1表达升高,心肌组织Bax、Cleaved-Caspase-3蛋白表达升高,Bcl-2蛋白表达降低(均P<0.05)。ICSⅡ+Selisistat组LVEDP、cTnI、TNF-α、IL-1β、细胞凋亡率、Ac-FOXO1表达、心肌组织Bax、Cleaved-Caspase-3蛋白表达低于Selisistat组,MAP、LVSP、LVEF、LVFS水平和SIRT1、Bcl-2蛋白表达高于Selisistat组(均P<0.05)。结论心肌缺血再灌注损伤大鼠ICSⅡ预处理后,可缓解心肌组织炎症损伤,改善心室功能,其机制可能与激活SIRT1/FOXO1通路有关。

Objective To observe the effects and mechanism of icarisideⅡ(ICSⅡ)on myocardial ischemia-reperfusion injury in rats.Methods The rats were divided into sham operation(Sham)group,model(Model)group,ICSⅡgroup,Selisistat[(silent information regulator 1,SIRT1)inhibitor]group,and ICSⅡ+Selisistat group.After pretreatment,the rat model of myocardial ischemia-reperfusion injury was established by ligation of anterior descending branch of left coronary artery.The changes of ventricular function were detected by ultrasound.HE staining was used to observe the changes of myocardial histopathology.The levels of serum interleukin-1β(IL-1β),cardiac troponin I(cTnI),and tumor necrosis factor(TNF-α)were measured by enzyme linked immunosorbent assay(ELISA).Tunnel staining was used to detect myocardial apoptosis.Western blot was used to detect the expressions of SIRT1,acetylated-forkhead box O1(Ac-FOXO1),Bcl-2 associated X protein(Bax),cysteinecontaining aspartate-specific proteases-3(Caspase-3),Cleaved-Caspase-3 and B-cell lymphoma-2(Bcl-2)proteins in myocardial tissue.Results Compared with Sham group,the left ventricular end-diastolic pressure(LVEDP)in model group increased,the mean arterial pressure(MAP),left ventricular systolic pressure(LVSP),left ventricular ejection fraction(LVEF)and left ventricular fraction shortening(LVFS)decreased,the levels of cTnI,TNF-αand IL-1βincreased,the apoptosis rate increased,the expression of SIRT1 decreased,the expression of Ac-FOXO1 increased,the expressions of Bax and Caspase-3 proteins in myocardial tissue increased,the expression of Bcl-2 protein decreased,and the differences were statistically significant(P<0.05).Compared with the Model group,the LVEDP in ICSⅡgroup decreased,the MAP,LVSP,LVEF and LVFS increased,the levels of cTnI,TNF-αand IL-1βincreased,the apoptosis rate decreased,the expression of SIRT1 increased,the expression of Ac-FOXO1 decreased,the expressions of Bax and Cleaved-Caspase-3 proteins in myocardial tissue decreased,the expression of Bcl-2 protein increased,and the differences were statistically significant(P<0.05);the LVEDP in Selisistat group increased,the MAP,LVSP and LVEF decreased,the levels of cTnI,TNF-αand IL-1βincreased,the apoptosis rate increased,the expression of SIRT1 decreased,the expression of Ac-FOXO1 increased,the expressions of Bax and Cleaved-Caspase-3 proteins in myocardial tissue increased,the expression of Bcl-2 protein decreased,and the differences were statistically significant(P<0.05).The LVEDP,cTnI,TNF-α,IL-1β,apoptosis rate,the expression of Ac-FOXO1,the expressions of Bax and Cleaved-Caspase-3 proteins in myocardial tissue of ICSⅡ+Selisistat group were lower than those of Selisistat group,while the MAP,LVSP,LVEF,LVFS,the expressions of SIRT1 and Bcl-2 were higher than those of Selisistat group,and the differences were statistically significant(P<0.05).Conclusion IcarisideⅡpretreatment can alleviate myocardial inflammatory injury and improve ventricular function in rats with myocardial ischemia-reperfusion injury,which may be related to activation of SIRT1-FOXO1 pathway.