Research On The Mechanism Of Autophagy In Myocardial Adaptation To Chronic Hypoxia In Cyanotic Congenital Heart Disease

Objective: Researching on the expression of autophagy in myocardial tissue of children with congenital heart disease,we investigate the expression of autophagy in chronic hypoxic adaptation of cardiomyocytes and discuss the role of autophagy in hypoxic cardiomyocytes.To provide a theoretical basis for the current treatment of hypoxic conditions how to reduce myocardial damage and improve the cyanotic congenital heart disease in children.Methods: Experimental group: 20 cases with the First Affiliated Hospital of Bengbu Medical College and Nanjing Children’s Hospital cardiac surgery from April 2015 to October 2016 in the treatment of children with congenital heart disease,the average age was 19.65 months.Control group: 20 cases of non cyanotic congenital heart disease were collected from the First Affiliated Hospital of Bengbu Medical College and Nanjing Children Hospital from April 2015 to October 2016 in the treatment of cardiac surgery,the average age was 16.55 months.The right ventricular outflow tract hypertrophy myocardial tissue was taken as the specimen,part of the size of 5 * 5 *5mm3 was placed in liquid nitrogen tank for Western-blotting detection,another part of the fast cut 1mm3,with 5% glutaraldehyde fixed,placed in the EP tube in 4 degrees to avoid light.After the sample of 1mm3 was made into ultrathin sections,the formation of autophagy in myocardial tissue was observed by electron microscope,we extract the myocardial tissue protein from the liquid nitrogen and detect the ratio of LC3 II/LC3 I and the expression level of Beclin-1 protein in myocardial cells by Western-blotting and make a statistical analysis in the two groups of myocardial tissues.Results: The experimental group and control group were observed by electron microscope.In the experimental group,the arrangement of myocardial tissue was disordered,the mitochondria were increased,a large number of organelles were degraded,endoplasmic reticulum was swollen,the organelle structure was fuzzy,and some of the organelles and proteins were seen.In the control group,the organelles were less degraded,and the arrangement of the filaments was not observed.The result of Western-blotting showed that the experimental group of children with congenital heart disease with high expression of LC3 II,and LC3 II /LC3 I ratio were significantly greater than those in non cyanotic group,the expression level of Beclin-1protein group was significantly higher than that of non cyanosis cyanosis group.SPSS18.0 software was used for the test,and the results showed that there were differences between the two groups in the expression of LC3 and Beclin-1(P < 0.05),indicating that the difference between the two groups was statistically significant and It was proved that the autophagy of myocardial tissue was obviously activated under hypoxia.Conclusion: 1.The formation of autophagosomes were found in children with cyanotic congenital heart disease in myocardial tissue,indicate the presence of autophagy phenomenon in anoxic myocardial cells.2.The expression of LC3 was higher in children with cyanotic congenital heart disease,and the ratio of LC3 II /LC3 I was significantly higher than that of the control group,the expression level of Beclin-1 protein in the experimental group was significantly higher than that in the control group.3.Autophagy in chronic myocardial hypoxia influence the survival of myocardium,may play a regulatory role in the occurrence and progression of cyanotic congenital heart disease.