秦皮甲素通过调节TLR/NF-κB途径抑制脂多糖诱导的心肌损伤

Esculin Inhibits Lipoplysaccharide-induced Myocardial Injury by Regulating TLR/NF-κB Pathway

目的研究秦皮甲素对脂多糖(lipopolysaccharide,LPS)诱导大鼠心肌损伤及TLR/NF-κB途径的影响。方法构建LPS诱导心肌损伤模型,将大鼠分为对照组、LPS组、秦皮甲素低剂量组(20 mg·kg^(-1))、秦皮甲素中剂量组(40 mg·kg^(-1))、秦皮甲素高剂量组(80 mg·kg–1)和阳性对照组(地塞米松2 mg·kg^(-1))。心脏超声检测心脏功能,HE染色检测心脏组织损伤程度。ELISA检测血液中肌钙蛋白(cardiac troponin I,cTnI),肌酸激酶同工酶[creatine kinase(CK)-MB,CK-MB],肌红蛋白(myoglobin,Mb),肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α),白介素-6(interleukin-6,IL-6),IL-1β,丙二醛(malondialdehyde,MDA),超氧化物歧化酶(superoxide dismutase,SOD)和髓过氧物酶(myeloperoxidase,MPO)的含量。Western blotting检测Toll样受体2(Toll-like receptor 2,TLR2),TLR4,骨髓分化因子88(myeloid differentiation factor 88,MyD88),白介素1受体相关激酶(interleukin-1 receptor-associated kinases,IRAK1)和磷酸化核因子-κB(phosphorylatednuclear factor-κB,p-NF-κB)的蛋白相对表达量。结果与LPS组相比,在秦皮甲素治疗后,心率、左室壁相对厚度和左心室射血分数均显著升高(P<0.05),而左室收缩末容积显著降低(P<0.05)。心肌酶cTnI、CK-MB和Mb的表达量显著下调(P<0.05);促炎细胞因子IL-6、TNF-α和IL-1β的表达量下调(P<0.05);氧化应激标记物中SOD含量显著升高(P<0.05),而MDA和MPO含量均显著降低(P<0.05);TLR2、TLR4、MyD88、IRAK1和p-NF-κB蛋白表达水平均显著下调(P<0.05)。结论秦皮甲素对LPS诱导心肌损伤具有保护作用,并抑制TLR/NF-κB信号通路。

OBJECTIVE To investigate the effects of esculin on lipopolysaccharide(LPS)-induced myocardialinjury and TLR/NF-κB pathway in rats.METHODS The myocardial injury model induced by LPS was established.Rats were randomly divided into control group,LPS group,esculin low dose group(20 mg·kg^(-1)),esculin middle dose group(40 mg·kg^(-1)),esculin high dose group(80 mg·kg^(-1))and positive control group(dexamethasone,2 mg·kg^(-1)).Cardiac function was detected by echocardiography,and the degree of cardiac histological damage was detected by HE staining.The content of cardiactroponin I(cTnI),creatine kinase(CK)-MB(CK-MB),myoglobin(Mb),tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),IL-1β,malondialdehyde(MDA),superoxide dismutase(SOD)and myeloperoxidase(MPO)in blood were detected by ELISA.The proteinexpressive levels of Toll-like receptor 2(TLR2),TLR4,myeloid differentiation factor 88(MyD88),interleukin-1 receptor-associated kinases(IRAK1)and phosphorylated-nuclear factor-κB(p-NF-κB)were detected by Western blotting in cardiac tissue.RESULTS Compared with the LPS group,the levels of heart rate,left ventricular wall thickness and left ventricular ejection fraction were significantly increased after esculin treatment(P<0.05),while left ventricular end systolic volume was significantly decreased(P<0.05).The expression of myocardial enzymes cTnI,CK-MB and Mb was significantly down-regulated(P<0.05).The expression of pro-inflammatory cytokines IL-6,TNF-α and IL-1β were down-regulated(P<0.05).The oxidative stress markers SOD content was increased significantly(P<0.05),while MDA and MPO content was decreased significantly(P<0.05).Protein expression levels TLR2,TLR4,MyD88,IRAK1 and p-NF-κB were significantly reduced(P<0.05).CONCLUSION Esculin has a protective effect on LPS-induced myocardial injury and inhibits TLR/NF-κB signaling pathway.