苦参素通过JAK2/STAT3通路抑制心肌缺血再灌注大鼠炎症反应

Effect of Oxymatrine on Inflammatory Response in Rats with Myocardial Ischemia-reperfusion

目的:探讨苦参素对心肌缺血再灌注(MIR)大鼠炎症反应的影响,并以Janus激酶2(JAK2)/信号转导与转录激活子3(STAT3)通路为切入点探讨其可能的作用机制。方法:将144只大鼠按随机数字表法分为6组:假手术组、模型组、维拉帕米(6 mg/kg)组和苦参素低剂量(25 mg/kg)、中剂量(50 mg/kg)、高剂量(100 mg/kg)组,每组24只。造模前7 d开始每日1次腹腔注射给药。末次给药30 min后,通过阻断左冠状动脉前降支30 min构建MIR大鼠模型。再灌注24 h后,观察心电图ST段变化,通过生物机能系统测定左心室收缩压(LVSP)、左心室舒张末期压(LVEDP)、左心室内压最大升高速率(+dp/dt_(max))和最大下降速率(-dp/dt_(max));分光光度法检测血浆心肌酶[肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)]活性;通过2,3,5-氯化三苯基四氮唑(TTC)染色、苏木素-伊红(HE)染色观察心肌梗死率和心肌组织病变;酶联免疫吸附实验(ELISA)法检测心肌组织炎性因子[肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)]含量;蛋白质印迹法(Western Blot)检测JAK2/STAT3通路蛋白和高迁移率族蛋白B1(HMGB1)表达。结果:苦参素预处理可明显降低MIR大鼠心电图ST段高度、LVEDP、心肌梗死率、血浆CK-MB、LDH活性、心肌组织TNF-α、IL-1β、IL-6含量及磷酸化JAK2(p-JAK2)/JAK2、磷酸化STAT3(p-STAT3)/STAT3表达比值和HMGB1相对表达量,可明显升高LVSP、+dp/dt_(max)、-dp/dt_(max),差异均有统计学意义(P<0.05)。苦参素上述作用具有一定的剂量依赖性,苦参素高剂量组作用最强。除+dp/dt_(max)、-dp/dt_(max)外,苦参素高剂量组对其他指标的作用均优于维拉帕米组(P<0.05)。结论:苦参素可能通过抑制JAK2/STAT3通路活化而减轻MIR大鼠炎症反应,对MIR大鼠心脏功能起保护作用。

Objective:To investigate the effect of Oxymatrine on the inflammatory response of myocardial ischemia-reperfusion(MIR)rats.Methods:According to the random number table method,144 rats were divided into 6 groups:sham operation group,model group,verapamil(6 mg/kg)group,and Oxymatrine low-dose(25 mg/kg),medium-dose(50 mg/kg),high-dose(100 mg/kg)groups,with 24 rats in each group.The rats were administered by intraperitoneal injection once a day for 7 days before modeling.Thirty minutes after the last administration,the rat left anterior descending coronary artery was blocked for 30 minutes.After reperfusion twenty-four hours,the ST segment changes of the electrocardiogram were observed,the left ventricular systolic pressure(LVSP)and end-diastolic pressure(LVEDP),the maximum rise rate of left ventricular pressure(+dp/dt_(max))and the _(max)imum drop rate of left ventricular pressure(-dp/dt_(max))were detected by biological function system.The activity of myocardial enzymes[creatine kinase-MB(CK-MB)and lactate dehydrogenase(LDH)]in plasma were detected by spectrophotometry.The myocardial infarction rate and myocardial tissue lesions were observed by 2,3,5-triphenyl tetrazolium chloride(TTC)staining and hematoxylin-eosin(HE)staining.The contents of inflammatory factors[tumor necrosis factor-α(TNF-α),interleukin(IL)-1β,and IL-6]in myocardial tissue were detected by enzyme-linkedimmunosorbent assay(ELISA),and the expression of Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)pathway proteins and high mobility group box 1(HMGB1)were detected by Western Blot.Results:Oxymatrine pretreatment could significantly reduce ST segment height,LVEDP,myocardial infarction rate,CK-MB,and LDH activities in plasma,TNF-α,IL-1β,IL-6contents in myocardial tissue,the expression ratio of p-JAK2/JAK2,p-STAT3/STAT3 and the relative expression of HMGB1,and it could significantly increase LVSP,+dp/dt_(max),-dp/dt_(max),all of the difference was significant(P<0.05).Oxymatrine pretreatment could significantly improve myocardial tissue lesions.The above effects of Oxymatrine showed certain dose dependence,and the high-doseOxymatrine group showed the strongest effect.Except for+dp/dt_(max) and-dp/dt_(max),the effects of Oxymatrine high-dose on other indexes were better than those of the verapamil group(P<0.05).Conclusion:Oxymatrine may reduce the inflammatory response in MIR rats by inhibiting the activation of JAK2/STAT3 pathway,and plays protective role on cardiac function in MIR rats.