Toll样受体4拮抗剂TAK-242对C57BL/6小鼠心肌缺血再灌注损伤的保护作用

TAK-242,an antagonist for Toll-like receptor 4,protects against myocardial ischemia/reperfusion injury in C57BL/6 mice

目的探讨TAK-242治疗对心肌缺血再灌注损伤(I/R)小鼠的保护作用及可能机制。方法将36只雄性C57BL/6小鼠随机分为3组:假手术组(sham组)、模型组(缺血30 min/再灌注24 h,I/R组)和治疗组〔I/R+TAK-242(3 mg/kg)〕。再灌注24 h后应用心脏超声检测小鼠心功能、TTC染色法测定心肌梗死面积、HE染色观察心肌病理改变、实时荧光定量PCR和Western印迹法检测心肌组织TLR4 m RNA和蛋白表达、ELISA检测血清IL-6、TNF-α、IL-10和高迁移率族蛋白B1(HMGB1)浓度。结果与sham组比较,I/R组小鼠左心室收缩期直径(LVIDs)缩短(P<0.01),左心室射血分数(LVEF)和左心室短轴缩短分数(LVFS)均有显著性降低(P<0.01),出现大面积心肌梗死以及严重心肌炎症病理改变,心肌TLR4表达上调(P<0.01),血清IL-6、TNF-α、IL-10和HMGB1浓度升高(P<0.01)。与I/R组比较,TAK-242治疗组小鼠LVIDs有所延长(P<0.05),LVEF和LVFS显著提高(P<0.01或P<0.05),心梗面积显著缩小(P<0.01),心肌炎症浸润减轻,心肌TLR4表达降低(P<0.05),血清促炎因子IL-6和TNF-α水平明显下降(P<0.01),而抗炎因子IL-10和HMGB1浓度进一步升高(P<0.01)。结论 TAK-242治疗对I/R小鼠心肌具有保护作用,其作用机制可能与抑制炎症反应有关。

Objective To investigate the effect of TAK-242,an antagonist for Toll-like receptor 4,against myocardial ischemia/reperfusion injury（I/R）in C57BL/6 mice along with the underlying mechanism. Methods C57BL/6Mice（n=36）were randomized into three groups：sham group,I（30 min）/R 24 h model group and I/R＋TAK-242（3 mg/kg）treatment group. At 24 h after reperfusion,cardiac function and myocardial infarct size were evaluated with echocardiography and triphenyltetrazolium chloride（TTC）,myocardial pathological pattern in mice was detected by HE staining,the m RNA and protein levels of TLR4 were determined by real time PCR and Western blot respectively,and the serum levels of IL-6,TNF-α,IL-10 and HMGB1 were detected by ELISA. Results Our results showed that left ventricular systolic diameters（LVID）were shortened（P〈0.01）,left ventricular ejection fraction（LVEF）and left ventricular short axis shortening fraction（LVFS）were both decreased significantly（P〈0.01）in following I/R mice.Myocardial infarction size was large and myocardial inflammatory cell infiltration was severe in I/R mice. The m RNA and protein levels of TLR4 were elevated（P〈0.01）,the serum levels of IL-6,TNF-α,IL-10 and HMGB1 in I/R mice were significantly increased compared with the sham group（P〈0.01）. We found that TAK-242 significantly extended LVID（P〈0.05）,increased LVEF and LVFS（P〈0.05）,reduced myocardial infarction and improved myocardial inflammatory cell infiltration,inhibited the m RNA and protein levels of TLR4（P〈0.05）,down-regulated the expression of IL-6 and TNF-α（P〈0.01）,and up-regulated IL-10 and HMGB1 compared with I/R group（P〈0. 01）. Conclusion Treatment with TAK-242 can significantly reduce myocardial ischemia/reperfusion injury partly via regulating inflammation.