灯盏花素对大鼠心肌缺血再灌注损伤心肌细胞凋亡及NF-kB通路信号分子α7nAChR、p65、IkB-α的影响

Influence of breviscapine on myocardial apoptosis and NF-kB pathway signaling molecules(α7nAChR, p65 and IkB-α) in rats with myocardial ischemia-reperfusion injury

目的观察灯盏花素对大鼠心肌缺血再灌注损伤心肌细胞凋亡及NF-kB通路信号分子α7nAChR、p65、IkB-α的影响。方法 40只SD大鼠随机均分为假手术组、缺血再灌注组、灯盏花素低剂量组(25 mg/kg·d)和灯盏花素高剂量组(50 mg/kg·d),每组各10只。4组均制备缺血再灌注模型,其中灯盏花素治疗组术前连续1周腹腔注射灯盏花素;假手术组以及缺血再灌注组分别注射等量的生理盐水。随后处死,取出心脏检测心肌组织梗死面积;TUNEL法检测心肌细胞的凋亡指数;蛋白印记法检测α7nAChR、p65、IkB-α蛋白的表达。结果缺血再灌注组较假手术组心肌梗死面积、心肌细胞凋亡指数以及IkB-α蛋白显著增加(P<0.01),p65和α7nAChR蛋白显著减少(P<0.05);灯盏花素高低剂量组较缺血再灌注组心肌梗死面积、心肌细胞凋亡指数以及IkB-α蛋白显著降低(P<0.01),p65和α7nAChR蛋白显著增加(P<0.05),并呈现剂量依赖性。结论灯盏花素预处理能有效减少大鼠心肌缺血再灌注损伤以及心肌细胞凋亡,其机制可能为上调α7nAChR,从而通过NF-kB通路抑制心肌细胞的凋亡,发挥心肌保护作用。

Objective To observe the influence of breviscapine on myocardial apoptosis and NF-kB pathway signaling molecules(α7nAChR,p65 and IkB-α)in rats with myocardial ischemia-reperfusion(IR)injury.Methods SD rats(n=40)were randomly divided into sham-operation group,IR group,low-dose breviscapine group(25 mg/kg·d)and high-dose breviscapine group(50 mg/kg·d,each n=10).The IR model was established in all 4 groups.The breviscapine groups were given intraperitoneal injection of breviscapine continuously for 1 week before PCI or CABG,and sham-operation group and IR group were given injection of normal saline in the same dose.After rats being sacrificed,the heart samples were collected for detecting myocardial infarct size.The apoptotic index of cardiomyocytes was detected by using TUNEL,and protein expressions ofα7nAChR,p65 and IkB-αwere detected by using Western blotting assay.Results The myocardial infarct size,apoptotic index of cardiomyocytes and IkB-αprotein increased significantly(P<0.01),and p65 andα7nAChR proteins decreased significantly(P<0.05)in IR group compared with sham-operation group.The myocardial infarct size,apoptotic index of cardiomyocytes and IkB-αprotein decreased significantly(P<0.01),and p65 andα7nAChR proteins increased significantly(P<0.05)in high-dose breviscapine group and low-dose breviscapine group compared with IR group in a dose-dependence manner.Conclusion The pretreatment of breviscapine can effectively relieve myocardial IR injury and reduce cardiomyocyte apoptosis,and the mechanism may be related to the up-regulation ofα7nAChR for inhibiting cardiomyocyte apoptosis via NF-kB pathway and playing a role of myocardial protection.