Research On The Mechanism Of Dilated Cardiomyopathy By Mass Spectrometry Based Proteomics And Data Mining Of The Genecards Database

Background Dilated cardiomyopathy(DCM)is a serious life-threatening disease worldwide,and the sudden cardiac death(SCD)caused by it is still an unresolved public health problem.According to statistics,the prevalence of DCM is as high as 1:250.The 5-year survival rate is about 50% and the10-year survival rate is about 25% after diagnosis.Although the main clinical manifestation of DCM is heart failure or arrhythmia,the first symptom of some patients is death,and forensic autopsy is required to confirm that it is a SCD caused by DCM.SCD often lack the main clinical symptoms and is diagnosed mainly on the basis of Hudson.Thus,how to diagnose DCM accurately and objectively is the focus and difficulty of current forensic pathology research.Therefore,the study of preclinical animal models and human samples is particularly important,looking for new biomarkers,elucidating the pathogenesis,early diagnosis of DCM,delaying the progression of the disease,reducing mortality and preventing sudden death are of great significance.Objective The purpose of this study is to establish a(DCM)model of dilated cardiomyopathy in SD rats,carry out proteomic analysis,and then screen out specific biomarkers as candidates,and explore its biological significance in the occurrence and development of DCM.In addition,in order to better understand the signal pathways related to DCM,the correlation between the differentially expressed proteins obtained by iTRAQ and the data set in Genecards database was analyzed,which provides a scientific theoretical basis for the discussion of pathogenesis,early diagnosis,determination of treatment targets,treatment monitoring,prognosis evaluation,sudden death prevention and judicial identification of DCM.Methods The DCM model of SD rats was established by intravenous injection of doxorubicin [DCM group(n=20),control group(n=10)].After the model was established by echocardiography and NT-pro BNP,the myocardial protein expression after DCM was detected by iTRAQ,and the DEPs were selected as candidate specific biomarkers,which were verified by PRM,transmission electron microscope.In addition,we analyzed the correlation between the DEPs obtained by iTRAQ and the data set in Genecards database,and screened and identified the signal pathways related to DCM through bioinformatics analysis.Result1.The establishment of DCM model Compared with the normal control group,the cardiac cavity of DCM group was significantly enlarged,the LVEF was significantly decreased,and NT-pro BNP significantly increased.Histopathology showed that the cardiac was significantly enlarged,myocardial cells were hypertrophy,disordered arrangement,interstitial loose edema,fibroblast proliferation,myocardial interstitial fiber connective tissue hyperplasia,indicating that the DCM model was successfully established by repeated tail vein injection of DOX.2.Differential protein analysis of DCM proteomics A total of 783 DEPs were identified in this study,of which 354 were up-regulated and 429 were down-regulated.Then randomly selected 5DEPs for PRM verification,thioredoxin domain 5(Txndc5),integrin α5(Itga5),citrate synthase(Cs),cytochrome c oxidase subunit 5A(Cox5a),and cardiac troponin T(Tnn T2)protein expression were consistent with those of iTRAQ.GO enrichment analysis found that the DEPs are mainly mitochondrial protein,and KEGG analysis found that the DEPs are mainly involved in metabolic pathways,oxidative phosphorylation,citric acid cycle(TCA cycle),myocardial contraction and other signal pathways.3.Association analysis of DCM disease target gene and iTRAQ proteomics The association analysis between DCM disease target gene and iTRAQ proteomic analysis showed that there were 215 co-DEPs.GO enrichment analysis found that the co-DEPs were mainly mitochondrial proteins,and KEGG analysis found that co-DEPs were mainly involved in metabolic pathways,oxidative phosphorylation,citric acid cycle(TCA cycle),myocardial contraction and other signal pathways.NADH dehydrogenases,cytochrome c oxidase subunits(COX5A),cytochrome C(CYC1),SDHA,SDHB and inorganic pyrophosphatase(PPA2)are mainly involved in the oxidative phosphorylation signal pathway.Citrate synthase(CS),succinate-Co A ligase(SUCLA2),pyruvate dehydrogenase E1(PDHA1),succinate dehydrogenase(SDH),pyruvate dehydrogenase complex(DLAT),dihydrolipoic acid dehydrogenase Enzyme(DLD),isocitrate dehydrogenase subunit(IDH3A)participate in TCA cycle signal pathway.Ryanodine receptor(RYR2),tropomyosin α 3 chain(TPM3),cytochrome c oxidase subunit(COX),cardiac troponin C(TNNC1),tropomyosin α chain(TPM1),troponin T(TNNT2),myosin regulated light chain 2(MYL2),troponin I(TNNI3),cytochrome C(CYC1)and myosin(MYH7)are involved in the signal pathway of muscle contraction.Conclusion In this study,a SD rat DCM model was successfully established.The differentially expressed proteins of the model are mainly distributed in mitochondria,and the protein levels of the pathways such as myocardial metabolism,oxidative phosphorylation,tricarboxylic acid cycle,and cardiac muscle contraction have been significantly increased.Changes,these changes are one of the important reasons leading to the occurrence of DCM.In addition,the use of multi-omics methods,that is,the correlation analysis between DCM disease target genes and differentially expressed proteins found that myocardial metabolism,oxidative phosphorylation,tricarboxylic acid cycle,and cardiac muscle contraction not only occur in acquired DCM,but also in familial Significant changes have also taken place in DCM.