Study On Mechanism Of The Role Of Citrate Lyase In Ut-b Gene Deficiency Cardiomyocytes

In order to prove whether ACLY,the key enzyme of glycolipid metabolism,participates in and regulates the disorder of lipid metabolism of cardiomyocytes caused by the deficiency of UT-B.The previous research found that UT-B gene knockout can lead to the metabolic remodeling of the mouse heart,and UT-B-/-mice will have the symptoms of cardiac hypertrophy,accompanied by different degrees of atrioventricular block,which will aggravated with aging.In addition,the study shows that ACLY expression is abnormal in some diseases related to lipid metabolism,such as obesity and diabetes.In recent years,there are few reports about the mechanism of ACLY and cardiovascular disease.The purpose of this study is to further confirm the role of UT-B in the remodeling of myocardial energy metabolism,to explore the expression and role of ACLY in myocardial hypertrophy caused by high urea and UT-B deficiency,to clarify that ACLY participates in the disorder of myocardial cell lipid metabolism caused by UT-B gene deficiency,and to further confirm that ACLY can regulate the disorder of myocardial lipid metabolism caused by UT-B gene deficiency,thus affecting the occurrence and development of myocardial hypertrophy exhibition.Methods:1)The normal cardiomyocytes(H9C2)were treated with 20 m M urea to establish a high urea cell model.The size and lipid accumulation of cardiomyocytes,the expression of cardiac mast marker protein(ANP)and citrate lyase(ACLY),and the changes of total cholesterol,triglyceride and high / low density lipoprotein contents with time were observed.2)The model of UT-B-deficient cardiomyocytes was established by using UT-B knockout cardiomyocytes.After being treated with isoproterenol(ISO),the size and lipid accumulation of UT-B-deficient cardiomyocytes under load or stimulation were observed.The expression of cardiac mast marker protein(ANP)and citrate lyase(ACLY)and the total cholesterol,triglyceride,high / low density lipoprotein contents were observed.3)Normal cardiomyocytes and UT-B-deficient cells were used.After treating with isoproterenol(ISO)and transfecting sh ACLY and empty vector,the expression of cardiac hypertrophy marker protein(ANP)and citrate lyase(ACLY)and the content of total cholesterol,triglyceride and high / low-density lipoprotein were observed and compared.Results:1)High urea can promote the disorder of lipid metabolism in cardiomyocytes,and the absence of UT-B is more likely to lead to cardiac hypertrophy.The results of immunofluorescence showed that the cell volume of normal cardiomyocytes increased significantly after urea loading(p < 0.05),and that of UT-B deficient cells increased significantly after ISO stimulation.The results of oil red O staining showed that there was lipid accumulation in normal myocardial cells under urea loading,and a large number of lipid accumulation in UT-B gene deficient cells stimulated by ISO.Western blotting showed that the expression of ANP and ACLY in urea loaded normal cardiomyocytes and ISO stimulated UT-B gene deficient cells increased over time.The results showed that the contents of total cholesterol,triglyceride and high /low-density lipoprotein were significantly higher(p < 0.05)in the urea loaded normal cardiomyocytes than those in the ISO treated UT-B gene deficient cardiomyocytes(p <0.05),showing a time-dependent manner,and the changes of low-density lipoprotein were the most obvious(p < 0.05).2)Intervention of ACLY expression can regulate cardiac hypertrophy caused by deficiency of UT-B gene.The results of Western blotting showed that compared with the control group,the expression of ANP and ACLY in normal cardiomyocytes and UT-B gene deficient cells was higher(p < 0.05),and the increase of UT-B gene deficient cells was more significant(p <0.05);compared with the model group,the expression of ANP and ACLY in cells after transfection of ACLY sh RNA was significantly lower(p < 0.05).Compared with the control group,the content of total cholesterol,triglyceride and high / low density lipoprotein in normal cardiomyocytes and UT-B gene deficient cells increased significantly after ISO treatment(p < 0.05),and the content of low density lipoprotein increased most significantly(p < 0.05);the content decreased significantly after ACLY-sh RNA transfection;the content of low density lipoprotein decreased more significantly after ACLY-sh RNA transfection(p < 0.05).Conclusion:Firstly,it is confirmed that high urea and UT-B gene deletion can lead to the disorder of lipid metabolism in cardiomyocytes.Secondly,it is clear that ACLY participates in the disorder of lipid metabolism in cardiomyocytes caused by UT-B gene deletion.Finally,interference with ACLY expression can regulate the disorder of lipid metabolism in cardiomyocytes caused by UT-B gene deletion and inhibit the occurrence and development of cardiac hypertrophy.