Study Of Quantitative And Lysine Acetylation,crotonylation,succinylation Proteomics Of Hypertrophic Cardiomyopathy

Sudden cardiac death(SCD)is an accidental fatal event,and its sudden and fatal characteristics often have serious impacts on society and families.The incidence of SCD was 50 to 100 per 100,000 people,and up to 75% of young SCD cases were related to hereditary heart disease.Hypertrophic cardiomyopathy(HCM)is a common hereditary heart disease,and the first manifestation of some HCM patients is SCD.It is currently believed that HCM is mainly caused by mutations of genes which encoding sarcomeric protein,but the specific molecular mechanism is still unclear.In this research,the myocardial tissues of HCM patients and healthy adults were used as the research object.Proteomic technology was applied to explore the protein profiles of the myocardial tissue of HCM patients,and to screen differentially expressed proteins so as to provide some scientific data for studying the pathogenesis of HCM.This research was divided into three parts:In the first part,we analyzed the myocardial tissues of healthy adults and HCM patients by quantitative proteomics technology labeled with tandem mass tag(TMT).In this experiment,we identified 98 proteins up-regulated and 56 proteins down-regulated in the HCM group.Bioinformatics analysis results showed that up-regulated proteins were mainly enriched in protein digestion and absorption pathways and focal adhesion pathways,while down-regulated proteins were enriched in nitrogen metabolism pathways and various amino acid metabolism pathways,suggesting that differentially expressed proteins in the myocardial tissue of HCM patients may be participated in a variety of metabolic processes of cardiomyocytes and the regulation of cytoskeleton homeostasis.These results provided new insights for elucidating the abnormal molecular mechanism of HCM and laid the foundation for studying the pathophysiological mechanism of HCM.To explore the differences in protein expression level of myocardial tissues in HCM patients with different gene mutations and to analyze the possible reasons for the different clinical manifestations of HCM patients,we performed TMT-labeled quantitative proteomic analysis on the myocardial tissues of 33 HCM patients with MYH7 gene mutations and 30 patients with MYBPC3 gene mutations.As a result,it was identified that the expression levels of 8 proteins were significantly different between the two groups.Compared with MYH7 gene mutations,4 proteins,including ATP synthase F(0)complex subunit C1(ATP5G1),were up-regulated in HCM patients with MYBPC3 gene mutations and 4 proteins were down-regulated.Gene ontology(GO)enrichment analysis results showed that differentially expressed proteins were mainly enriched in ATPase activity.However,the differentially expressed proteins failed to be enriched in any KEGG pathway,and the STRING analysis results showed that there was no obvious interaction relationship between the differentially expressed proteins.Our results suggested that there was a small difference between the myocardial protein expression profiles of HCM patients with MYH7 gene mutation and MYBPC3 gene mutation;ATP5G1 may be related to the different phenotypes of the two.In the third part,we analyzed the global profiles of lysine acetylation(Kac),lysine crotonylation(Kcr),and lysine succinylation(Ksu)in cardiac tissues from patients with HCM and healthy controls by TMT-based quantitative proteomics.We identified 528 Kac sites in 246 proteins,194 Kcr sites in 139 proteins,and 107 Ksu sites in 89 proteins that were significantly different in the HCM tissues compared with the controls.The differentially abundant acetylated proteins were mainly distributed in mitochondria,while crotonylated and succinylated proteins were mainly distributed in the cytoplasm.The results of bioinformatics analysis indicated that acetylated proteins in HCM may be involved in various metabolic processes,crotonylated proteins may be related to heart development and muscle contraction,but succinylated proteins may play a role in cardiac hypertrophy in HCM.The above results suggested that these three types of acylation modifications may play different roles in HCM,and it is speculated that the regulatory mechanisms of the three acylation modifications may be different.The comparative study of Kac,Kcr and Ksu in the myocardial tissue of HCM patients will help to deepen the understanding of the role of protein post-translational modification in the pathophysiological mechanism of HCM.In this study,quantitative proteomic technology was used to analyze the differential expression of proteins in the myocardial tissues of HCM patients.Compared with protein expression levels of normal myocardial tissue,the expression levels of various structural proteins and metabolism-related proteins in the myocardial tissue of HCM patients had significantly changed,suggesting that these proteins may be related to the pathogenesis of HCM;The difference of protein expression profiles of myocardial tissues between HCM patients with MYH7 gene mutation and MYBPC3 gene mutation was not significant,and ATP5G1 may be related to the phenotypic differences in HCM patients with two different gene mutations;There were significant differences in the characteristics of protein acetylation,crotonylation and succinylation in the myocardial tissue of HCM patients,and the regulatory mechanisms of the three types of acylation may be different.