A Study On The Level Of Inflammatory Cytokines And Autophagy In Dilated Cardiomyopathy Rats

Background: Heart failure is a terminal stage of the occurrence and development of cardiovascular disease,such as coronary heart disease,valvular disease,cardiomyopathy and so on.It has become one of the most urgent public health problems in the world.Dilated cardiomyopathy is one of the causes of heart failure,which has higher morbidity and mortality.The etiology and pathogenesis of dilated cardiomyopathy remain to be further studied.It is believed that heart failure can be regarded as a systemic inflammatory disease characterized by recurrent inflammation.Inflammatory cytokines and autophagy play an important role in the process of heart failure.Autophagy is helpful or harmful to heart has not been concluded yet.Statins can not only reduce blood fat,but also can anti oxidative stress,anti inflammation,improve endothelial function,prevent and treat atherosclerosis.It is recommended to treat ischemic heart disease.However,the curative effect of dilated cardiomyopathy and other causes of heart failure remains controversial.Trimetazidine as a drug for cardiovascular protection,can improve myocardial energy metabolism,improve endothelial function,anti oxidative stress and anti inflammation,but its effect on the level of autophagy in cardiomyocytes is not known.Objects:To study the survival status,cardiac function,myocardial morphology,inflammatory cytokines,autophagy in dilated cardiomyopathy rats,and to investigate the role of inflammatory cytokines and autophagy in heart failure.To observe the changes of cardiac function,myocardial morphology,inflammatory cytokines and autophagy after the application of statins or trimetazidine,explore the possible mechanism and provide theoretical basis for the treatment of heart failure caused by dilated cardiomyopathy.Methods:In this study,42 rats were randomly selected from 52 adult male specific pathogen free rats.These rats were injected doxorubicin into pleural to make dilated cardiomyopathy model,the other 10 rats were used as control group with intraperitoneal injection of equivalent normal saline.After 10 weeks,31 rats with dilated cardiomyopathy(11 rats died during the model preparation)were randomly divided into three groups:rosuvastatin group(RSFTT group,n=10),the rats were treated with 2.5mg/kg/d rosuvastatin for 4 weeks;trimetazidine group(QMTQ group,n=11),the rats were treated with 15 mg/kg/d trimetazidine for 4 weeks;Saline group(n=10),the rats were given equivalent normal saline for 4 weeks.After the course of treatment,the cardiac function was evaluated by echocardiography and hemodynamics,the morphology of myocardial tissue was observed by HE staining,Masson staining,TUNEL and DAPI fluorescence staining,the levels of serum IL-1?,IL-6,TNF-? and other inflammatory factors were tested by ELISA,the expression of autophagy related protein and autophagy related gene m RNA were detected by Western-Blot and RT-PCR.Results:1?In the process of preparing dilated cardiomyopathy model,11 rats died,the mortality rate was 21.15%.Rats in control group had the best overall situation,lively and active,without hair loss and anorexia;The Saline group had the worst overall condition,malaise,poor activity and eating,severe hair loss and dull hair,the final weight was significantly lower than initial weight(P<0.01);RSFTT group and QMTQ group were better than Saline group,the final weight was significantly higher(P<0.01).2?Compared with Control group,the NT-pro BNP,hs-Tn T,lung index,ventricular weight ratio,LVIDs and LVIDd increased,LVEF,LVFS,LVPWs,LVPWd,CO,SV,+dp/dtmax and-dp/dtmax decreased in Saline group(P<0.05 or P<0.01);Compared with Saline group,the NT-pro BNP,hs-Tn T,lung index,LVIDs and LVIDd decreased,LVEF,LVFS,CO,SV,+dp/dtmax and-dp/dtmax increased in RSFTT group and QMTQ group(P<0.05 or P<0.01).3?HE staining,Masson staining,TUNEL and DAPI fluorescence staining showed that:the size,morphology,structure and arrangement of myocardial cells in Control group were normal;Myocardial cells of Saline group appeared vacuolar degeneration,apoptosis.Cytoplasmic staining were loose,edema,cell gap became larger,the blue collagen deposition near the myocardial cells showed extensive vascular ruptur,blood cell infiltration,and muscle fibers disarray;Compared with Saline group,RSFTT group and QMTQ group had different degrees on improvement in the above-mentioned histological changes.4? ELISA was used to test the levels of inflammatory factors(IL-1,IL-6,TNFand hs-CRP)indicated that:compared with Control group,the levels of inflammatory factors in Saline group were significantly higher(P<0.01);Compared with Saline group,QMTQ group and RSFTT group can significantly reduce the level of inflammatory factors(P<0.01).5?Western-Blot and RT-PCR showed that:in Saline group,the expression of P62 was lower(P<0.05),the expression of LC3 B,LC3B II/I and autophagy related gene(Beclin1,Atg5,Atg7,Atg14)m RNA was much higher than that of Control group(P<0.01),the level of autophagy was up-regulated;.In RSFTT group and QMTQ group,the expression of P62 was higher(P<0.05 or P<0.01),the expression of LC3 B and autophagy related gene m RNA were significantly lower than that of Saline group(P<0.01),the level of autophagy was down-regulated.Compared with RSFTT group,QMTQ group had more significant effect on the level of autophagy.Conclusions:1?The level of inflammatory factors IL-1??IL-6?TNF-? and hs-CRP may be positively correlated with the deterioration of cardiac function in dilated cardiomyopathy rats.2?The damage of cardiomyocytes in dilated cardiomyopathy rats may be related to the increase of autophagy level.3?Inflammation and autophagy may play a synergistic role in the progression of heart failure in rats with dilated cardiomyopathy;4?Rosuvastatin and trimetazidine can alleviate myocardial injury and improve cardiac function in rats with dilated cardiomyopathy by reducing inflammatory factors.5?Rosuvastatin and trimetazidine may improve the cardiac function in rats with dilated cardiomyopathy by inhibiting the inflammatory response and down-regulating the level of autophagy in myocardial cells.