黄连碱预处理对心肌缺血再灌注损伤大鼠JNK/p38MAPK信号通路的影响

Effect of Coptisine Pretreatment on JNK/p38MAPK Signaling Pathway in Rats with Myocardial Ischemia-reperfusion Injury

目的:探讨黄连碱预处理对心肌缺血再灌注(MI/RI)大鼠c-Jun氨基末端激酶(JNK)/促分裂素原活化蛋白激酶(p38MAPK)信号通路的影响。方法:将60只大鼠随机分为MI/RI组、假手术组、黄连碱低剂量组(黄连碱-L组,50 mg/kg黄连碱)、黄连碱中剂量组(黄连碱-M组,100 mg/kg黄连碱)、黄连碱高剂量组(黄连碱-H组,200 mg/kg黄连碱)及黄连碱-H+激活剂组(50 mg/kg黄连碱+25 mg/L JNK/p38MAPK通路激活剂茴香霉素),每组10只。除假手术组外,其余各组均进行冠状动脉结扎构建MI/RI大鼠模型,造模后,观察血流动力学参数左室内压最大上升(LVdp/dt_(max))、左室内压最大下降速率(LVdp/dt_(min))、收缩压以及舒张末压变化;采集大鼠腹部主动脉血,评估心肌损伤程度指标肌酸激酶同工酶(CK-MB)及乳酸脱氢酶(LDH)含量;分离心肌组织,检测心肌组织病理学变化、细胞凋亡、炎性因子[肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)]水平及JNK/p38MAPK通路相关蛋白表达。结果:与假手术组比较,MI/RI组存在大量炎性细胞浸润、组织结构紊乱,病理损伤严重,LVdp/dt_(max)、LVdp/dt_(min)、收缩压均降低,但凋亡率、舒张压、LDH、CK-MB、TNF-α、IL-6含量、p-JNK/JNK、p-p38MAPK/p38MAPK表达增加(P<0.05);与MI/RI组比较,黄连碱-L组、黄连碱-M组、黄连碱-H组病理损伤得到改善,LVdp/dt_(max)、LVdp/dt_(min)、收缩压均增加,凋亡率、舒张压、LDH、CK-MB、TNF-α、IL-6含量、p-JNK/JNK、p-p38MAPK/p38MAPK表达降低(P<0.05);与黄连碱-H组比较,黄连碱-H+激活剂组病理损伤进一步加剧,LVdp/dt_(max)、LVdp/dt_(min)、收缩压均降低,但凋亡率、舒张压、LDH、CK-MB、TNF-α、IL-6含量、p-JNK/JNK、p-p38MAPK/p38MAPK表达增加(P<0.05)。结论:黄连碱预处理可通过抑制JNK/p38MAPK通路减轻MI/RI大鼠心肌损伤。

Objective:To investigate the effect of coptisine pretreatment on c-Jun amino-terminal kinase(JNK)/mitogen-activated protein kinase(p38MAPK)signaling pathway in myocardial ischemia-reperfusion(MI/RI)rats.Methods:Sixty rats were randomly divided into MI/RI group,sham operation group,low dose of coptisine(coptisine-L,50 mg/kg coptisine)group,medium dose of coptisine(coptisine-M,100 mg/kg coptisine)group,and high dose of coptisine(coptisine-H,200 mg/kg coptisine)group and coptisine-H+activator(50 mg/kg coptisine+25 mg/L JNK/p38MAPK pathway activator-anisomycin)group,10 rats in each group.MI/RI rat model was constructed by coronary artery ligation in all groups except the sham operation group.After modeling,the hemodynamic parameters of left chamber pressure maximum rise(LVdp/dt_(max)),decline rate(LVdp/dt_(min)),systolic blood pressure,and end diastolic blood pressure were observed.The contents of creatine kinase isoenzyme(CK-MB)and lactate dehydrogenase(LDH)were evaluated by collecting aorta blood from rats.Myocardial tissue was isolated,and myocardial histopathological changes,apoptosis,TNF-α,interleukin-6(IL-6)levels,and JNK/p38MAPK pathway-related protein expression were detected.Results:Compared with the sham operation group,MI/RI group showed a large number of inflammatory cells infiltration,tissue structure disorder,serious pathological damage,LVdp/dtmax,LVdp/dtmin,systolic blood pressure decreased,however,apoptosis rate,end-diastolic blood pressure,LDH,CK-MB,TNF-α,IL-6 content,P-JNK/JNK,P-P38MAPK/p38MAPK expression increased(P<0.05).Compared with MI/RI group,the pathological damage of coptisine-L group,coptisine-M group and coptisine-H group were improved,and LVdp/dt_(max),LVdp/dt_(min) and systolic blood pressure increased,and apoptosis rate,end diastolic blood pressure,LDH,CK-MB,TNF-α,IL-6 content,P-JNK/JNK,P-P38MAPK/p38MAPK expression decreased(P<0.05).Compared with the coptisine-H group,the pathological damage of coptisine-H+activator group was further aggravated,and LVdp/dtmax,LVdp/dtmin and systolic blood pressure decreased,however,apoptosis rate,end diastolic blood pressure,LDH,CK-MB,TNF-α,IL-6 content,P-JNK/JNK,P-P38MAPK/p38MAPK expression increased(P<0.05).Conclusion:Pretreatment with coptisine could reduce myocardial injury in MI/RI rats by inhibiting JNK/p38MAPK pathway.