心包腔转染AAV1介导SERCA2a基因过表达对快速起搏兔右心房实验研究

AAV1 mediated sarcoplasmic reticulum Ca^(2+) ATPase gene overexpression by pericardial cavity transfection in rapid right atrial-paced rabbit

目的探讨心肌肌浆网Ca2+-ATP酶(sarcoplasmic reticulum Ca2+ATPase,SERCA2a)基因过表达对快速起搏右心房新西兰大白兔SERCA2a活性和蛋白的影响。方法新西兰大白兔动物模型随机分为假手术组(A组)、AAV1/EGFP+心房颤动(房颤)模型组(B组)、AVV1/SERCA2a+房颤模型组(C组),每组各10只。B组注射含报告基因的AAV1-EGFP 500μL,C组注射含靶基因的AAV1-SERCA2a500μL。转染4周后,行短期快速起搏新西兰大白兔右心房24h,处死各组动物,行BCA法测定SERCA2a蛋白活性和免疫组织化学检测SERCA2a在心肌中的蛋白表达情况。结果基因转导后4周,B组SERCA2a蛋白活性及蛋白含量明显低于A组(P<0.01),C组SERCA2a蛋白活性及蛋白含量与A组比较差异无统计学意义(P>0.01)。结论快速起搏兔右心房致快速心律失常模型兔右心房SERCA2a活性和蛋白含量下降,心包腔转染AAV1介导SERCA2a基因过表达,可增加SERCA2a活性和蛋白含量。

Abstract： Objective To study the effect of the overexpression of sarcoplasmic reticulum Ca2＋-ATPase （SERCA2a） mediated by AAV1 on the SERCA2a activity and protein in rapid right atrial-paced rabbit models. Methods Thirty New Zealand rabbits were divided into sham operation group （group A）, AAV1/green fluorescent protein （EGFP） ＋ atrial fibrillation （AF） group （group B）, and AAV1/SERCA2a＋AF group （group C）, with 10 rabbits in each group. AAV1- EGFP （500 μL for each rabbit） was directly and intramyocardially injected to rabbits in group B, and AAV1-SERCA2a （500 μL for each rabbit） was injected to rabbits in group C. Four weeks after gene transfection, the right atrium underwend short-term rapid pacing, and 24 hours later all rabbits in each group were sacrified. The expression of SERCA2a at the protein level was detected by immunohistochemistry and the activity of SERCA2a was detected by BCA method. Results Four weeks after gene transfection, the activity and protein content of SERCA2a were significantly lower in group B than those in group A （P〈0.05）, and there was no significant difference between group A and group C （P〉 0. 05）. Conclusion SERCA2a activity and protein content decrease in rapid arrhythmia models induced and established by rapid right atrial pacing. The overexpression of SERCA2a gene mediated by AAV1 can increase the SERCAga activity and protein content.