川芎多糖调节p38 MAPK/NF-κB信号通路对大鼠心肌缺血再灌注损伤的影响

Effects of Ligusticum Chuanxiong Polysaccharide on Myocardial Ischemia-reperfusion Injury in Rats by Regulating p38 MAPK/NF-κB Signaling Pathway

目的:探讨川芎多糖(LCPS)调节p38丝裂原活化蛋白激酶(p38 MAPK)/核因子-κB(NF-κB)信号通路对大鼠心肌缺血再灌注损伤(MIRI)的影响。方法:将144只大鼠数字编码后按照随机数字表法分为假手术组、模型组、盐酸维拉帕米(VH)组(20 mg/kg)和LCPS低剂量组(50 mg/kg)、LCPS中剂量组(100 mg/kg)、LCPS高剂量组(200 mg/kg),每组24只大鼠。给药预处理14 d后,采用阻断冠状动脉左前降支30 min制备MIRI大鼠模型。再灌注2 h后,通过2,3,5-三苯基氯化四氮唑(TTC)染色法、心脏超声法、苏木精-伊红(HE)染色法检测大鼠心肌梗死面积、心功能指标[左室舒张末期压力(LVEDP)、左室收缩末期压力(LVESP)、左室内压最大上升速率(+dp/dt_(max))、左室内压最大下降速率(-dp/dt_(max))]和心肌组织病理变化;酶联免疫吸附法(ELISA)检测血清心肌酶和心肌组织炎性因子水平;蛋白免疫印迹法(Western Blot)检测心肌组织p38 MAPK/NF-κB信号通路相关蛋白表达。结果:与假手术组比较,模型组大鼠心肌梗死面积、LVEDP、病理评分、心肌酶[乳酸脱氢酶(LDH)、肌酸激酶同工酶(CK-MB)、心肌肌钙蛋白I(cTnI)]水平、炎性因子[白细胞介素(IL)-1β、IL-6、肿瘤坏死因子(TNF)-α]水平、p-p38 MAPK、p-NF-κB p65蛋白相对表达量及p-p38 MAPK/p38 MAPK、p-NF-κB p65/NF-κB p65比值升高,LVESP、+dp/dt_(max)、-dp/dt_(max)降低,差异均有统计学意义(P<0.05)。与模型组比较,VH组、LCPS中剂量组和LCPS高剂量组心肌梗死面积、LVEDP、病理评分、心肌酶水平、炎性因子水平、p-p38 MAPK、p-NF-κB p65蛋白相对表达量及p-p38 MAPK/p38 MAPK、p-NF-κB p65/NF-κB p65比值降低,LVESP、+dp/dt_(max)、-dp/dt_(max)升高,差异均有统计学意义(P<0.05),且LCPS上述效应呈一定的剂量依赖性。除+dp/dt_(max)、-dp/dt_(max)、IL-1β外,LCPS高剂量组对其他指标的影响优于VH组(P<0.05)。结论:LCPS对大鼠MIRI和心功能有保护作用,其机制可能与抑制p38 MAPK/NF-κB信号通路及其介导的炎症反应有关。

Objective:To investigate the effect of ligusticum chuanxiong polysaccharide(LCPS)on myocardial ischemia-reperfusion injury(MIRI)in rats by regulating the p38 mitogen activated protein kinase(p38 MAPK)/nuclear factor-κB(NF-κB)signaling pathway.Methods:After numerical coding,144 rats were divided into sham operation group,model group,verapamil hydrochloride(VH)group(20 mg/kg),LCPS low-dose group(50 mg/kg),LCPS medium-dose group(100 mg/kg),and LCPS high-dose group(200 mg/kg)according to random number table method,with 24 rats in each group.After 14 days of pretreatment,the MIRI rat model was established by blocking the left anterior descending coronary artery for 30 min.After 2 h reperfusion,myocardial infarction size and cardiac function indexes[left ventricular end-diastolic pressure(LVEDP),left ventricular end-systolic pressure(LVESP),maximum rise rate of left ventricular pressure(+dp/dt_(max)),maximum fall rate of left ventricular pressure(-dp/dt_(max))]were detected by 2,3,5-triphenyletetrazolium chloride(TTC)staining,cardiac ultrasonography and hematoxylin-eosin(HE)staining respectively and pathological changes of myocardial tissue in rats were observed.The levels of serum myocardial enzymes and inflammatory factors were detected by enzyme-linked immunosorbent assay(ELISA).The expression of p38 MAPK/NF-κB signal pathway related proteins in myocardial tissue were detected by Western Blot.Results:Compared with the sham operation group,myocardial infarction area,LVEDP,pathological score,levels of myocardial enzymes[lactate dehydrogenase(LDH),creatine kinase isoenzyme(CK-MB),cardiac troponin I(cTnI)],inflammatory factors[interleukin(IL)-1β,IL-6,tumor necrosis factor(TNF)-α],p-p38 MAPK,the relative expression of MAPK and p-NF-κB p65 protein and the ratio of p-p38 MAPK/p38 MAPK and p-NF-κB p65/NF-κB p65 in the model group increased,while LVESP,+dp/dt_(max) and-dp/dt_(max) decreased,with statistical significance(P<0.05).Compared with the model group,myocardial infarction area,LVEDP,pathological score,levels of myocardial enzymes,inflammatory factor,the relative expression of p-p38 MAPK,p-NF-κB p65 protein and the ratio of p-p38 MAPK/p38 MAPK and p-NF-κB p65/NF-κB p65 in the VH group,LCPS medium-dose group and LCPS high-dose group decreased,LVESP,+dp/dt_(max),-dp/dt_(max) increased,and the differences were statistically significant(P<0.05).The above effects of LCPS were dose-dependent.Except for+dp/dt_(max),-dp/dt_(max) and IL-1β,LCPS high-dose group showed better effects on other indexes than VH group(P<0.05).Conclusion:LCPS showed protective effects on MIRI and cardiac function in rats,its mechanism might be related to the inhibition of p38 MAPK/NF-κB signaling pathway and it mediated inflammatory response.