The Basic Study On Retinoic Acid Induced Non-compaction Of Ventricular Myocardium

Non-compaction of ventricular myocardium(NVM),also known as’hypertrabeculation’ or ’spongy myocardium’,is a special kind of cardiomyopathy.It is characterized by two-layered myocardial structure comprising of a thin compacted layer on the epicardial side and a much thicker non-compacted layer on the endocardial side,which can be seen multiple prominent trabeculations and deep intertrabecular recesses communicating with the ventricular cavity and having blood flow in and out.In the first chapter,we systematically reviewed the research progress of NVM at home and abroad,including its nomenclature,epidemiology,classification,etiology and pathogenesis,pathological anatomy,pathophysiology and clinical manifestations,clinical diagnosis and differential diagnosis,treatment and prognosis.Because of high incidence,unknown etiology,no effective treatment,high mortality and poor prognosis of NVM,it has important scientific and clinical value to establish animal models of NVM to reveal its pathogenesis.This project is mainly aimed at the mouse model of retinoic acid(RA)-induced NVM and related basic research.The research contents were divided into three parts:1.Discussing how to use RA to induce pregnant mouse offsprings to establish fetal mouse model of NVM;2.Using the tandem mass tag(TMT)-based quantitative proteomics technology to detect differential protein and quantificationally analyze the heart tissue of NVM after successfully establishing mouse model of NVM;3.Using the parallel reaction monitoring(PRM)technique to validate and quantify the differential protein of NVM,and then discover the potential proteins associated with NVM,which will provide a research foundation for the subsequent functional validation of proteins,the exploration of the possibility in the pathogenesis and potential therapeutic targets of NVM.The first part:According to the previous research reports about the close relationship between the precise concentration of RA and the development of normal embryonic myocardial compaction,the hypothesis that using excessive RA to interfere with the process of embryonic myocardial compaction in pregnant mice and induce the offsprings of pregnant mouse to establish NVM model was put forward.In our study,the pregnant mice at 8.5 days after pregnancy were given 70 mg/kg ATRA to induce fetal mouse model of NVM.Histopathology confirmed that the offsprings of pregnant mouse in RA intervention group showed typical pathological characteristics of NVM.It was further found that the average body weight of offsprings of pregnant mice in RA intervention group was significantly lower than that of control groups(P<0.0001).After 10 days of ATRA administration,the average body weight of female mice decreased significantly compared with that before administration,showing significant statistical difference(P<0.0001).CONCLUSION:Excess ATRA could be used to induce NVM of fetal mice heart.The study also suggests that excessive ATRA may be involved in the energy metabolism of pregnant mice and their offsprings.This mouse model is the basis for further study of TMT-based quantitative proteomics technology to detect and quantificationally analyze the heart tissue of NVM.The second part:After the establishment of NVM model in the offsprings of pregnant mouse induced by RA,the basic research of NVM induced by RA was carried out by TMT-based quantitative proteomics technology.Sixty eight differential proteins were were screened in RA intervention group(RA)and blank control group(Control),Forty eight differential proteins were screened in RA intervention group(RA)and DMSO control group(DMSO).Gene Ontology(GO)functional annotation and KEGG(Kyoto Encyclopedia of Genes and Genomes)pathway enrichment analysis showed that the common differentially expressed proteins and their pathways between RA and the two control groups were mainly manifested in energy metabolism and coagulation function.CONCLUSION:According to a large number of studies on the function of these proteins,it is preliminarily speculated that the possibility of NVM induced by RA in offspring of pregnant rats is more related to abnormal energy metabolism,while the possibility of NVM ventricular thrombosis is more related to abnormal blood coagulation function.The specific pathogenesis of NVM needs further study.The third part:After screening and analyzing differentially expressed proteins in NVM heart tissues by TMT-based quantitative proteomics,PRM technology was used to validate and quantitatively analyze differentially expressed proteins.Twelve peptides of six differential proteins including kininogen-1(KNG1),alpha-1-antitrypsin(A1AT),apolipoproteinA-I(ApoAI),beta-2-glycoprotein 1(β2GP1),tubulinbeta-4A chain(TUBB4A)and aquaporin-4(AQP4)in nine heart samples of control,DMSO and RA groups were quantitatively analyzed by PRM.The results showed that the expression of these six proteins was significant differences,which was consistent with the relative quantitative results detected by TMT.The structure,function and related pathways of these six proteins and their possible association with NVM were analyzed and summarized,which will provide further research directions for further functional verification of NVM-related proteins,understanding the pathogenesis and targeted therapy of NVM.