葛根素通过TLR4/NF-κB信号通路对心力衰竭大鼠心肌炎症反应的影响

Effect of puerarin on myocardial inflammation in rats with heart failure through TLR4/NF-κB signaling pathway

目的:通过Toll样受体4(TLR4)/核转录因子κB(NF-κB)炎症通路,探讨葛根素对心力衰竭大鼠心肌炎症反应的影响。方法:皮下注射异丙肾上腺素(5 mg/kg,共7 d)建立心力衰竭大鼠模型,并设置为模型组、葛根素组、TLR4激活剂组(RS09,25μg/kg)、TLR4抑制剂组(TAK-242,0.5 mg/kg)、葛根素+TLR4激活剂组,每组20只。另取20只大鼠为正常对照组。超声心动图检测心功能;HE染色观察心肌组织病理损伤;TUNEL法检测心肌组织细胞凋亡;ELISA法检测心肌组织炎症因子IL-6、IL-1β、肿瘤坏死因子-α(TNF-α)水平;免疫组化法检测TLR4、巨噬细胞活化标志物-F4/80表达;Western blot检测TLR4/NF-κB通路、MyD88、IL-1受体相关激酶(IRAK)、半乳糖凝集素3(Galectin-3)蛋白表达。结果:与正常对照组相比,模型组大鼠心肌细胞坏死、炎症浸润及凋亡严重,心功能下降,炎症因子释放、巨噬细胞活化、TLR4/NF-κB通路蛋白表达均升高(P<0.05)。葛根素及TLR4抑制剂能同等程度的改善心力衰竭大鼠心肌细胞坏死、炎症浸润及凋亡等病理损伤,提高心功能、降低炎症反应、抑制巨噬细胞活化、降低TLR4/NF-κB通路活化(P<0.05)。TLR4激活剂可促进TLR4/NF-κB通路活化、加重心力衰竭大鼠心肌细胞损伤、凋亡及心功能损伤,并削弱葛根素的上述作用(P<0.05)。结论:葛根素可能通过抑制TLR4/NF-κB通路活化,降低心肌炎症反应,发挥抗心力衰竭作用。

Objective:To investigate the effect of puerarin on myocardial inflammation in rats with heart failure from the Tolllike receptor 4(TLR4)/nuclear transcription factor-κB(NF-κB)inflammatory pathway.Methods:The rat model of heart failure was established by subcutaneous injection of isoproterenol(5 mg/kg for 7 days),and was divided into model group,puerarin group,TLR4 activator group(RS09,25μg/kg),TLR4 inhibitor group(TAK-242,0.5 mg/kg),puerarin+TLR4 activator group,with 20 rats in each group.Another 20 rats were selected as normal control group.Echocardiography was used to detect heart function;HE staining was used to observe pathological damage of myocardial tissue;TUNEL method was used to detect apoptosis of myocardial tissue cells;ELISA method was used to detect the levels of inflammatory factors IL-6,IL-1βand tumor necrosis factor-α(TNF-α)in myocardial tissue;immunohistochemical method was used to detect the expression of TLR4 and macrophage activation marker-F4/80;Western blot was used to detect the protein expressions of TLR4/NF-κB pathway,MyD88,IL-1 receptor-associated kinase(IRAK)and Galectin-3.Results:Compared with the normal control group,the necrosis,inflammatory infiltration and apoptosis of rat myocardial cells were severe in the model group,the heart function was decreased,the inflammatory factor release,macrophage activation,and TLR4/NF-κB pathway protein expression were increased(P<0.05).Puerarin and TLR4 inhibitors could improve the pathological damage of heart failure rats such as myocardial cell necrosis,inflammatory infiltration and apoptosis to the same extent,improve heart function,reduce inflammatory response,inhibit macrophage activation and reduce TLR4/NF-κB pathway activation(P<0.05).TLR4 activator could promote the activation of TLR4/NF-κB pathway,aggravate myocardial cell damage,apoptosis and cardiac function damage in rats with heart failure,and weaken the above-mentioned effects of puerarin(P<0.05).Conclusion:Puerarin may inhibit the activation of TLR4/NF-κB pathway,reduce myocardial inflammation,and play an anti-heart failure effect.