皮质抑素通过p38 MAPK信号通路抑制急性心肌梗死后心力衰竭大鼠氧化应激及心肌细胞凋亡

Cortistatin Inhibits Oxidative Stress and Cardiomyocyte Apoptosis in Rats with Post-acuate Myocardial Infarction Heart Failure through p38 MAPK Signaling Pathway

目的 探究皮质抑素通过p38丝裂原活化蛋白激酶(p38 MAPK)信号通路对急性心肌梗死后心力衰竭(HF-AMI)大鼠氧化应激及心肌细胞凋亡的影响。方法 40只SD大鼠随机分为假手术组、模型组、皮质抑素高剂量组(CST-H组)和皮质抑素低剂量组(CST-L组),每组10只。通过手术结扎冠状动脉左前降支建立HF-AMI大鼠模型。CST-H组和CST-L组腹膜内注射皮质抑素[175.0 mg/(kg·d)和87.5 mg/(kg·d)],其余组腹膜内注射生理盐水。超声心动图检测大鼠心功能;苏木素-伊红(HE)染色检测大鼠心肌病理学变化;酶联免疫吸附实验(ELISA)试剂盒检测大鼠超氧化物歧化酶(SOD)、丙二醛(MDA)和活性氧(ROS)含量;末端脱氧核苷酸转移酶介导的dUTP缺口末端标记(TUNEL)染色检测大鼠心肌细胞凋亡;蛋白质印迹法(Western Blot)检测大鼠B淋巴细胞瘤-2(Bcl-2)抗体、Bcl-2相关X蛋白(Bax)抗体、磷酸化丝裂原活化蛋白激酶激酶-6(p-MKK6)抗体、丝裂原活化蛋白激酶激酶-6(MKK6)、磷酸化p38 MAPK(p-p38 MAPK)和p38 MAPK蛋白表达。结果 与假手术组相比,模型组大鼠心功能下降,血流动力学障碍,心肌排列紊乱,且伴有炎性细胞浸润,MDA和ROS含量、心肌细胞凋亡率、p-MKK6/MKK6和p-p38 MAPK/p38 MAPK表达明显升高(P<0.05),SOD含量明显降低(P<0.05);与模型组相比,皮质抑素呈剂量依赖性改善HF-AMI大鼠心功能、血流动力学和心肌病理学变化,降低MDA和ROS含量、心肌细胞凋亡率、p-MKK6/MKK6和p-p38 MAPK/p38 MAPK表达(P<0.05),升高SOD含量(P<0.05)。结论 皮质抑素通过抑制p38 MAPK信号通路,抑制氧化应激和心肌细胞凋亡,改善HF-AMI大鼠心功能。

Objective To investigate the effect of cortistatin(CST) on oxidative stress and cardiomyocyte apoptosis in rats with post-acuate myocardial infarction heart failure(HF-AMI) through p38 mitogen-activated protein kinase(p38 MAPK) signaling pathway.Methods Forty SD rats were randomly divided into sham operation group, model group, CST-H group, and CST-L group, with 10 rats in each group.The HF-AMI rat model was established by ligating the left anterior descending coronary artery.The rats in CST-H and CST-L groups were injected intraperitoneally with cortistatin[175.0 mg/(kg·d) and 87.5 mg/(kg·d)],and the rats in remaining groups were injected with normal saline.Echocardiography was used to detect cardiac function in rats.Hematoxylin and eosin staining was used to detect myocardial pathological changes.Enzyme Linked Immunosorbent Assay(ELISA) kit was used to detect superoxide dismutase(SOD),malondialdehyde(MDA),and reactive oxygen species(ROS) in rats.Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling(TUNEL) staining was used to detect rat cardiomyocyte apoptosis.Western Blot was used to detect rat Bcl-2,Bax, mitogen-activated protein kinase kinase 6(MKK6),p-MKK6,p-p38 MAPK,and p38 MAPK protein expression.Results Compared with sham operation group, the cardiac function of model group was better, hemodynamic disturbance, myocardial arrangement disorder, and inflammatory cell infiltration, MDA and ROS content, myocardial apoptosis rate, p-MKK6/MKK6 and p-p38/p38 expression were significantly increased(P<0.05),and SOD content was significantly decreased(P<0.05).Compared with model group, cortistatin improved cardiac function and blood flow of HF-AMI rats in a dose-dependent manner changes, significantly reduced MDA and ROS content, myocardial cell apoptosis rate, p-MKK6/MKK6,and p-p38 MAPK/p38 MAPK expression(P<0.05),and significantly increased SOD content(P<0.05).Conclusion Cortistatin can improve cardiac function in rats with HF-AMI,inhibit oxidative stress and cardiomyocyte apoptosis by inhibiting p38 MAPK signaling pathway.