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目的研究重组1型腺相关病毒(rAAV1)介导的肌质网钙离子ATP酶2a(SERCA2a)基因转导对慢性心力衰竭(HF)beagle犬的治疗作用及可能的机制。方法经快速右心室起搏建立beagle犬的慢性HF模型。16只beagle犬分为4组:对照组(n=4),HF组(n=4),HF+EGFP组(n=4)和HF+SERCA2a组(n=4)。应用开胸心肌内注射术,分别将携带EGFP基因rAAV1和携带SERCA2a基因rAAV1导入HF+EGFP组和HF+SERCA2a组的beagle犬心肌,剂量为1×1012/ml,而对照组和HF组未进行任何处理。基因转导后30d,应用超声心动图、血流动力学检测各组beagle犬的心脏收缩和舒张功能、Western blotting检测SERCA2a蛋白表达水平,TUNEL法检测心肌细胞的凋亡指数,免疫组织化学染色检测Bax的表达。结果在基因转导后30d,HF+SERCA2a组SERCA2a蛋白表达水平较HF组明显增加,随着SERCA2a表达增加心功能也得到改善,左室收缩压峰值(LVSP)、左室舒张末压(LVEDP)、左室内压最大上升速率(LV+dp/dtmax)和左室内压最大下降速率(LV-dp/dtmax)均接近对照组水平,较HF组明显改善(P<0.05)。SERCA2a基因治疗后心肌细胞凋亡指数、Bax表达比HF组显著降低(P<0.05)。结论SERCA2a基因转导能够治疗慢性心力衰竭,改善心功能,抑制心肌细胞凋亡。
Objective To investigate the therapeutic effect of recombinant adeno-associated virus 1 (rAAV1) mediated by sarcoplasmic reticulum calcium ATPase 2a (SERCA2a) gene transduction on beagle dogs with chronic heart failure (HF) and its possible mechanism. Methods The chronic HF model of beagle dogs was established by rapid right ventricular pacing. Sixteen beagle dogs were divided into 4 groups: control group (n = 4), HF group (n = 4), HF + EGFP group (n = 4) and HF + SERCA2a group (n = 4). The myocardium of beagle dogs carrying EGFP gene rAAV1 and SERCA2a gene rAAV1 were introduced into HF + EGFP group and HF + SERCA2a group respectively at the dose of 1 × 1012 / ml, while the control group and HF group were not performed Any deal. Thirty days after gene transduction, the cardiac contractile and diastolic function of beagle dogs in each group were measured by echocardiography, the expression of SERCA2a protein was detected by Western blotting, the apoptosis index was detected by TUNEL, the expression of SERCA2a was detected by immunohistochemical staining Bax expression. Results The expression of SERCA2a protein in HF + SERCA2a group was significantly higher than that in HF group at 30 days after gene transduction. The cardiac function was also improved with the increase of SERCA2a expression. The left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP) (LV + dp / dtmax) and LV-dp / dtmax (LV-dp / dtmax) were significantly higher than those in control group (P <0.05). After SERCA2a gene therapy, the apoptosis index and Bax expression were significantly lower than those in HF group (P <0.05). Conclusion SERCA2a gene transduction can treat chronic heart failure, improve cardiac function and inhibit cardiomyocyte apoptosis.