| BackgroundAcute myocardial infarction has the highest incidence and mortality rates in cardiovascular diseases.Cardiac remodeling after myocardial infarction is the root cause of the development of heart failure,which is due to a series of complex molecular and cellular mechanisms caused by changes in myocardial structure,function and phenotype,manifested as pathological hypertrophy of myocardial cells,myocardial cell apoptosis and excessive myocardial fibrosis.Apoptosis of myocardial cells aggravates ventricular remodeling,leading to the development of heart failure and causing serious cardiac consequences.Therefore,targeted inhibition of apoptosis is an important therapeutic strategy to delay cardiac remodeling.Several studies have shown that the ASK1-JNK pathway plays a key role in the pathogenesis of ventricular remodeling by promoting apoptosis.Chinese medicine has a long history,and long-term practice has proved satisfactory in the treatment of chest pain and heartache.A number of fund project studies have shown that Yiqihuoxue drugs can significantly improve myocardial function after myocardial infarction and reduce cardiomyocyte apoptosis,but whether it can reduce cardiomyocyte apoptosis by regulating the ASK1-JNK signaling pathway to play a role in protecting the heart still needs to be further studied.Therefore,design related experiments to explore whether the mechanism of Yiqi huoxue drugs on myocardial infarction is related to the regulation of ASK1-JNK pathway to improve cardiomyocyte apoptosis.ObjectiveThe purpose of this study was to investigate the effect of Yiqihuoxue drugs on the molecular mechanism of cardiomyocyte apoptosis in myocardial infarction rats by regulating the ASK1-JNK signaling pathway.MethodThe rat model of myocardial infarction was prepared by ligating the anterior descending coronary artery(LAD)through thoracotomy.Rats with successful modeling were randomly divided into four groups:model group,Yiqihuoxue group,perindopril group,and sham operation group(as a control group).The sham operation group was threaded but not ligated.On the next day of the operation,the corresponding drugs were given to each group by intragastric treatment,and the sham operation and model group were given the same amount of distilled water.Once a day,continuous administration for 4 weeks and the index of myocardial tissue on the 28th day of each group of rats was detected.Echocardiography was used to evaluate the changes in the left ventricular structure and function of each group of rats;the cell morphological changes of the marginal zone tissues of myocardial infarction were observed by HE staining;the apoptosis of myocardial cells in rats was detected by TUNEL staining;dihydroethylidine(DHE)Fluorescent probe to detect ROS concentration;Western blotting technology to detect the expression levels of Bax,Bcl-2,c-caspase 3,Trx,P-ASK1,ASK1,P-JNK,and JNK protein in the marginal zone;the expression of P-JNK is detected by immunofluorescence.ResultExperiment 1 1.Ultrasonic examination of the left ventricular function of rats in each group:Compared with the sham operation group,the LVEF and LVFS of the model group were significantly reduced(P<0.01),and the LVESD,LVEDD,LVESV,and LVEDV were significantly increased(P<0.01);compared with the model group,the LVESD,LVEDD,LVESV,and LVEED decreased in the Yiqihuoxue group(P<0.01 or P<0.05),and the LVESD,LVESV,and LVEDV in the perindopril group decreased(P<0.01 or P<0.05),LVEDD decreased,but no statistical significance.2.HE staining;Atrophy of myocardial cells,rupture of myocardial fibers,and infiltration of more inflammatory cells in the model group.The myocardial cells in the dual-use medicine group were relatively ordered,and the fibrous tissue proliferation and inflammatory cell infiltration at the infarct site were improved compared with the model group,and the degree of cell structure damage was less.Experiment 2 1.Rat cardiomyocyte apoptosis index:Compared with the sham operation group,the model group cardiomyocyte apoptosis index increased significantly(P<0.01);compared with the model group,the dual-use drug group rat cardiomyocyte apoptosis index decreased significantly(P<0.01).2.Rat Bax,Bcl-2,c-caspase 3 protein expression results:compared with the sham operation group,the model group Bax,c-caspase 3 expression were significantly increased(P<0.01).Bcl-2 expression and Bcl-2/Bax were significantly reduced(P<0.01).Compared with the model group,the expression of Bax protein in Yiqihuoxue group decreased(P<0.01),Bcl-2 and Bcl-2/Bax increased significantly(P<0.05,P<0.01),there was no significant difference in c-caspase 3 protein expression(P>0.05);rats in the perindopril group had decreased Bax(P<0.01),Bcl-2/Bax ratio increased(P<0.05),and Bcl-2 showed an increasing trend,c-caspase 3 has a downward trend,but the difference is not statistically significant(P>0.05).Experiment 3 1.ROS generation level:The ROS fluorescence intensity of the model group was significantly higher than that of the sham operation group(P<0.01);the ROS fluorescence intensity of the dual-use drug group was significantly decreased compared with the model group(P<0.01).2.The effect of Yiqihuoxue drugs on the expression of Trx,ASK1,P-ASK1,JNK,and P-JNK protein in myocardial tissue:Compared with the sham-operated rats,the expression of Trx in the model group decreased significantly(P<0.01),P-ASK1,P-JNK protein expression was significantly up-regulated(P<0.01);compared with the model group,Yiqihuoxue drugs reduced the expression levels of P-ASK1,P-JNK(P<0.01 or P<0.05),Trx has an upward trend and ASK1 has a downward trend,but the difference is not statistically significant(P>0.05).There was no statistically significant difference in JNK expression between groups(P>0.05),3.P-JNK immunofluorescence staining results:P-JNK in the sham operation group was expressed in a small amount in the cytoplasm and nucleus,while the fluorescence signal in the model group was mainly distributed in the nucleus and most of the cytoplasm close to the nucleus.Yiqihuoxue group and perindopril group have a certain amount of expression in the nucleus and cytoplasm,and the fluorescence intensity is weaker than that in the model group.Conclusions1.Yiqihuoxue drugs can improve the contraction and relaxation of the heart,improve ventricular compliance,and reduce myocardial ischemic injury.2.Yiqihuoxue drugs can reduce the number of TUNEL positive cells,increase the Bcl-2/Bax ratio,promote the expression of anti-apoptotic factor Bcl-2,reduce the release of proapoptotic factor Bax,and effectively inhibit cell apoptosis.3.The protective mechanism of Yiqihuoxue drugs on myocardial infarction rats involves inhibiting ASK1-JNK signaling pathway and exerting anticardiomyocyte apoptosis effect. |
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