黄芪甲苷通过TLR4/p38MAPK信号通路抑制脂多糖诱导的小鼠心肌损伤

Inhibitory effect of astragaloside IV on myocardial injury induced by lipopolysaccharide-in mice by TLR4/p38 MAPK signaling pathway

目的:探讨黄芪甲苷(astragaloside IV)通过TLR4/p38MAPK信号通路对脂多糖(LPS)诱导的C57BL/6J小鼠急性心肌损伤的作用,并阐明其作用机制。方法:小鼠30只随机分为5组,分为空白对照组、脂多糖组、黄芪甲苷40mg/kg组、黄芪甲苷80mg/kg组、3-去氮腺苷10mg/kg(阳性对照)组。黄芪甲苷给药组给予黄芪甲苷14 d、3-去氮腺苷组给予3-去氮腺苷14 d后,腹腔注射脂多糖建立急性内毒素心肌损伤模型。采用射血分数(EF)、缩短分数(FS)、左心室舒张末期内径(LVIDd)、左心室收缩末期内径(LVIDs)等指标观察小鼠心脏功能;采用免疫组化检测心肌组织中ED1炎性细胞浸润情况;Western Blot检测TLR4、p38MAPK、pp38MAPK的表达情况;应用酶联免疫吸附测定法(ELISA)检测血清中TNF-α、IL-1β、IL6的含量;采用RT-PCR检测心肌组织中BNP mRNA的表达情况。结果:与空白对照组相比,脂多糖组的射血分数(EF)、缩短分数(FS)、左心室舒张末期内径(LVIDd)、左心室收缩末期内径(LVIDs)明显降低,而血清中TNF-α、IL-1β和IL6含量增加,组织中ED1、TLR4、p38MAPK、p-p38MAPK的表达明显增加。与脂多糖组相比,黄芪甲苷(40、80mg/kg)组均能明显提高EF、FS、LVIDd、LVIDs,以及明显降低TNF-α、IL-1β、IL6的含量及ED1、TLR4、p38MAPK、p-p38MAPK的表达。结论:黄芪甲苷对脂多糖引起的心肌炎症具有明显的抑制作用,可能是通过TLR4/p38MAPK信号通路起作用,并有效改善由脂多糖导致的心肌损伤。

Objective： To investigate the protective effect of astragaloside IV through TLR4/p38 MAPK signaling pathway on acute myocardial injury induced by lipopolysaccharide in C57 BL/6 J mice and to elucidate its mechanism of anti-myocardial inflammation. Methods： C57 BL/6 J mice were randomly divided into 5 groups,6 rats in each group,the control group,lipopolysaccharide group,40 mg/kg astragaloside group,80 mg/kg astragaloside group,10 mg/kg 3-deazaadenosine（positive control） group. Mice in astragaloside groups were given astragaloside IV for 14 days. The positive control group 3-deazaadenosine group was treated with 3-deazaadenosine for 14 days,and intraperitoneal injection of lipopolysaccharide was used to establish acute endotoxin myocardial injury model. The ejection fraction（EF）,shortening fraction（FS）,left ventricular end diastolic diameter（LVIDd） and left ventricular end-diastolic diameter（LVIDs） were used to observe the cardiac function; ED1 inflammatory cells in myocardium were detected by immunohistochemistry. Expressions of TLR4,p38 MAPK and p-p38 MAPK were detected by western blot. Levels of TNF-α,IL-1β and IL6 in serum were detected by enzyme-linked immunosorbent assay（ELISA）;The expression of BNP mRNA in myocardium was detected by RT-PCR. Results： Compared with the control group,the ejection fraction（EF）,shortening fraction（FS）,left ventricular end diastolic diameter（LVIDd） and left ventricular end systolic diameter（LVIDs） were significantly decreased in the model group,but expressions of TNF-α,IL-1β,IL6,ED1,TLR4,p38 MAPK and p-p38 MAPK were significantly increased. Compared with the model group. 40,80 mg/kg astragaloside IV significantly increased EF,FS,LVIDd,LVIDs and expressions of TNF-α,IL-1β,IL6,ED1,TLR4,p38 MAPK and p-p38 MAPK were significantly decreased in a dose-dependent manner. Conclusion： Astragaloside IV has obvious inhibitory effect on LPS-inducing myocardial inflammation and can play a role in TLR4/p38 MAPK signaling pathway and can effectively improve the myocardial injury caused by it.