| Objective: atrial fibrillation is a subject of cardiovascular disease, we hope to find an effective way to cure atrial fibrillation and not affect the electrophysiological of the ventricles. Study on the mechanisms of AF showed: atrial electrical remodeling is the main reason for ionic remodeling of atrial fibrillation maintenance, calcium overload play an important role, and the expression of SERCA 2a in atrial myocytes is the key calcium cycle imbalance, this subject is based on animal model of AF production stability, through the heart of AVV9 virus vector specific infection, the application of molecular methods of SERCA 2a gene transfer on atrial muscle cell gene Tiaobu, observe the expression of SERCA2 protein, transgenic and inducibility of atrial fibrillation, atrial myocytes using the patch clamp technique to record the action potential and its dispersion, Ca2+ current, impact assessment of SERCA 2a gene transfer on atrial myocytes electrophysiology, pathology the physiological and clinical outcome. Evaluation of the safety of genetically modified virus AAV9 vector and the molecular mechanism in SERCA 2a gene therapy for atrial fibrillation and provide a theoretical basis and a new way of thinking for studies on the mechanism and treatment of atrial fibrillation. This study included(1) the comparison of the effectiveness and safety of the ATP gene in the cytoplasm of the 9 type of gland related virus mediated by different transfection methods.(2) study on the effect of AAV9-SERCA 2a gene transfection on atrial structural remodeling and electrical remodeling in atrial fibrillation(AF) animal model.(3) the effect of AVV9-SERCA 2a gene transfection on L type calcium current in acute atrial fibrillation model. Methods: 60 male SD rats were randomly divided into 2 groups according to the gene transfection method. The group was divided into three groups: AAV9-SERCA 2a-EGFP group, AAV9-EGFP group and physiological saline group. The effectiveness and safety of different methods were detected. In the second part of this paper, 60 New Zealand white rabbits were randomly divided into 4 groups, AF group, rAAV9+EGFP+AF group, rAAV9+SERCA 2a+EGFP+AF group and sham operation group, 15 rats in each group. Acute atrial fibrillation model was established after transfection. Detection of animal models, the determination of atrial fibrillation, and the expression of SERCA 2a and LVDCCa1 c proteins in the right atrium. 9 New Zealand white rabbits were divided into 3 groups: AF group, rAAV9+SERCA 2a+EGFP+AF group and sham operation group, 3 rats in each group. Effect of SERCA 2a gene transduction on L- type calcium current in acute atrial fibrillation model. Results: the first part of this paper: 1. The expression of Western protein in Blot SERCA 2a was significantly higher than that in liver and kidney, and the expression of IPI was higher than that of IMI group(P<0.01). 2) gene was transferred into the 28 d, IPI group of the rat’s ECG normal, observation time, no arrhythmia occurs, IMI group 2 rats(which the transfected NS group and transfection AAV9-SERCA 2a-EGFP group 1) ventricular premature beat. 3) gene 28 d, AAV9-EGFP, AAV9-SERCA 2a-EGFP,, AST, ALT, BUN,, CRE and NS were not significantly different. In the second part of this paper, the AF group and rAAV9+EGFP+AF group were 4h after 1 AERP150, and the control group was shortened(P < 0.05). There was no significant difference between AF group and rAAV9+EGFP+AF group(P=0.05), rAAV9+EGFP+SERCA 2a+AF group(P<0.05), h 8 AERP150, AERP150 group and rAAV9+EGFP+AF group were significantly reduced(P<0.05) 2 rAAV9+SERCA 2a+EGFP+AF, but did not reach statistical difference(P>0.05), EF value was significantly decreased, and the difference was statistically significant(P<0.05). The parameters of rAAV9+EGFP+AF group were significantly improved compared with that of the AF group(P>0.05). In the third part of this paper, the amplitude and current density of L- type calcium current in atrial myocytes were decreased obviously after 24 h. The peak current density of 24 h group was significantly lower than that of SERCA 2a group, and the difference was statistically significant(P<0.05). Conclusions: 1. The AAV9-SERCA 2a gene was not significantly damaged by the method of myocardial injection, tail vein injection and pericardial cavity injection, and no significant damage to liver and kidney and heart function were not induced in the experimental rats. No inflammatory reaction was caused. Two kinds of transfection methods are safe and effective. IPI was superior to IMI in the transfection efficiency and side effects. 2) AAV9-SERCA 2a gene transfection can significantly improve atrial muscle structural remodeling and electrical remodeling in acute atrial fibrillation model. 3) SERCA 2a gene therapy can reduce the calcium overload of cardiac cells in patients with acute atrial fibrillation, and reduce the effect of atrial fibrillation on the current density of Ica-L. The results suggest that SERCA 2a gene therapy can reduce the calcium overload in patients with acute atrial fibrillation, reduce the effect of atrial fibrillation on Ica-L current density, which has positive significance to prevent atrial electrical remodeling and mechanical remodeling, thereby reducing the occurrence and maintenance of atrial fibrillation. |
PDF Full Text Request