SIRT1信号通路介导葛根素抵抗脓毒症心肌损伤的机制研究

Study on the mechanisms of the protective effects of puerarin against sepsis-induced myocardial injury by the SIRT1 signaling pathway

目的 明确沉默信息调控因子1(SIRT1)信号通路在葛根素缓解脓毒症心肌损伤中的具体作用。方法 将C57小鼠随机分为假手术(sham)组,葛根素(Pue)处理组,脓毒症(sepsis)组,脓毒症+葛根素(sepsis+Pue)组,EX527 (SIRT1抑制剂)+脓毒症+葛根素(EX527+sepsis+Pue)组以及EX527+脓毒症(EX527+sepsis)组。通过小鼠盲肠结扎穿孔法构建脓毒症小鼠模型。EX527+sepsis+Pue组和EX527+sepsis组小鼠盲肠结扎穿孔前通过腹腔注射给予5 mg/(kg·d) EX527,共给药3次。sepsis+Pue组和EX527+sepsis+Pue组小鼠盲肠结扎穿孔后通过腹腔注射给予单剂量的葛根素(10 mg/kg)。盲肠结扎穿孔后48 h,检测各组小鼠左室射血分数(LVEF)、左室短轴缩短率(LVFS)、心肌活性氧(ROS)产量、凋亡率、SIRT1和Ac-p53的表达量以及血清内TNF-α和IL-1β含量。结果 与sham组相比,Pue组小鼠上述指标无明显变化(P>0.05)。与sham组相比,sepsis组小鼠LVEF、LVFS以及SIRT1的表达量明显降低,心肌ROS产量、凋亡率、Ac-p53表达量、血清内TNF-α和IL-1β含量明显增高(P<0.05)。与sepsis组相比,sepsis+Pue组小鼠LVEF、LVFS以及SIRT1的表达量明显增高,心肌ROS产量、凋亡率、Ac-p53表达量、血清内TNF-α和IL-1β含量明显降低(P <0.05)。EX527+sepsis+Pue组抑制SIRT1信号通路明显减弱了葛根素抵抗脓毒症心肌损伤作用(P<0.05)。结论 SIRT1信号通路通过抑制氧化应激损伤、炎症反应和心肌凋亡,介导了葛根素抵抗脓毒症心肌损伤的作用。

Objective To clarify the role of the silent information regulator 1(SIRT1)signaling pathway in the protective effects of puerarin(Pue)against myocardial injury caused by sepsis.Methods C57 mice were randomly divided into sham group,Pue group,sepsis group,sepsis+Pue group,EX527+sepsis+Pue group and EX527+sepsis group.A mouse model of sepsis was established by cecal ligation and perforation(CLP).EX527[5 mg/(kg·d)]was administered by intraperitoneal injection before CLP for three times in EX527+sepsis+Pue group and EX527+sepsis group.A single dose of puerarin(10 mg/kg)was administered by intraperitoneal injection after CLP in sepsis+Pue group and EX527+sepsis+Pue group.Forty-eight hours after CLP,the left ventricular ejection fraction(LVEF),left ventricular fraction shortening(LVFS),myocardial reactive oxygen species(ROS)production,apoptotic ratio,serum TNF-αand IL-1βlevels,and the expression levels of SIRT1 and Ac-p53 were measured.Results No statistic difference in the parameters mentioned above were found between sham group and Pue group(P>0.05).Compared with sham group,LVEF,LVFS and the expression of SIRT1 were significantly decreased,while the myocardial ROS production,apoptotic ratio,the expression of Ac-p53,and serum TNF-αand IL-1βlevels were significantly increased in sepsis group(all P<0.05).Compared with sepsis group,LVEF,LVFS and the expression of SIRT1 were significantly increased,while the myocardial ROS production,apoptotic ratio,the expression of Ac-p53,and serum TNF-αand IL-1βlevels were significantly decreased in sepsis+Pue group(all P<0.05).Inhibition of SIRT1 significantly attenuated the protective effects of puerarin on myocardial injury caused by sepsis in EX527+sepsis+Pue group(P<0.05).Conclusion SIRT1 signaling pathway mediates the protective effects of puerarin against myocardial injury caused by sepsis by inhibiting oxidative stress,inflammatory response and myocardial apoptosis.