益母草碱抑制ERK/NF-κB信号通路对心力衰竭大鼠心肌细胞凋亡的影响

Effect of Leonurine on Cardiomyocyte Apoptosis in Rats with Heart Failure by Inhibiting ERK/NF-κB Signaling Pathway

目的:观察益母草碱抑制细胞外调节蛋白激酶(ERK)/核转录因子κB(NF-κB)信号通路对心力衰竭(HF)大鼠心肌细胞凋亡的影响。方法:将大鼠随机分为Control组、HF组,低剂量益母草碱(L-益母草碱)组、高剂量益母草碱(H-益母草碱)组及ERK抑制剂组。采用腹腔注射阿霉素法建立HF模型,HF模型建立成功后根据分组进行给药干预,连续14 d。利用彩色多普勒动物超声仪测量心功能指标[左室射血分数(LVEF)、左室收缩末期内径(LVESD)、左室舒张末期内径(LVEDD)、左室短轴缩短率(LVFS)]变化;末端脱氧核苷酸转移酶介导的dUTP缺口末端标记测定法(TUNEL)检测心肌细胞凋亡情况;免疫组化法检测心肌组织凋亡相关蛋白表达情况;蛋白免疫印迹法(Western Blot)检测心肌组织ERK/NF-κB信号通路相关蛋白表达情况。结果:与Control组比较,HF组LVEF、LVFS及心肌组织Bcl-2蛋白表达均减少,LVESD、LVEDD、心肌细胞凋亡率及心肌组织Bax蛋白表达均增加(P<0.05);与HF组比较,L-益母草碱组、H-益母草碱组、ERK抑制剂组LVEF、LVFS及心肌组织Bcl-2蛋白表达均增加,LVESD、LVEDD、心肌细胞凋亡率及心肌组织Bax蛋白表达均减少(P<0.05)。与Control组比较,HF组心肌组织磷酸化ERK(p-ERK)、磷酸化NF-κB抑制蛋白(p-IκBα)、细胞核NF-κB p65蛋白均增加(P<0.05);与HF组比较,H-益母草碱组、ERK抑制剂组心肌组织p-ERK、p-IκBα、细胞核NF-κB p65蛋白水平均减少(P<0.05)。结论:益母草碱可抑制HF大鼠心肌细胞凋亡,改善心功能,可能通过抑制ERK/NF-κB信号通路激活而实现。

Objective:To observe the effect of leonurine on cardiomyocyte apoptosis in rats with heart failure(HF)by inhibiting extracellular regulatory protein kinase(ERK)/nuclear factorκB(NF-κB)signaling pathway.Methods:The rats were randomly divided into Control group,HF group,low-dose leonurine(L-leonurine)group,high-dose leonurine(H-leonurine)group and ERK inhibitor group.The HF model was established by intraperitoneal injection of doxorubicin.After the successful establishment of HF model,drug was given for 14 consecutive days.Left ventricular ejection fraction(LVEF),left ventricular end-systolic diameter(LVESD),left ventricular end-diastolic diameter(LVEDD),and left ventricular short-axis shortening rate(LVFS)were detected by color Doppler ultrasound.Cardiomyocyte apoptosis was detected by termina-l deoxynucleotidyl transferase mediated nick end labeling(TUNEL).The expression of apoptosis-related proteins in myocardial tissue was detected by immunohistochemistry.The protein expression of ERK/NF-κB signaling pathway was detected by Western Blot.Results:Compared with Control group,LVEF,LVFS and the expression of Bc-l 2 protein in myocardial tissue of the HF group were decreased,while LVESD,LVEDD,rate of cardiomyocyte apoptosis and Bax protein in myocardial tissue were increased(P<0.05).Compared with HF group,LVEF,LVFS,and the expression of Bc-l 2 protein in myocardial tissue of the L-leonurine group,H-leonurine group,and ERK inhibitor group were increased,while LVESD,LVEDD,and rate of cardiomyocyte apoptosis and Bax protein in myocardial tissue were decreased(P<0.05).Compared with the Control group,the levels of phosphorylated ERK(p-ERK),phosphorylated inhibitory protein of NF-κBα(p-IκBα),and NF-κB p65 protein in the HF group were increased(P<0.05).Compared with the HF group,the protein levels of p-ERK,p-IκBα,and NF-κB p65 in myocardial tissue of H-leonurine group and ERK inhibitor group were decreased(P<0.05).Conclusion:Leonurine could inhibit cardiomyocyte apoptosis and improve cardiac function in HF rats,it was possibly related inhibiting the ERK/NF-κB signaling pathway.