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目的研究心肌肌浆网Ca2+-ATP酶(SERCA2a)基因过表达对慢性缺血性心力衰竭(HF)小型猪心功能的改善作用。方法使用Ameroid缩窄环束扎小型猪前降支起始段,4周后行超声心动和血流动力学检查确认心功能下降,放免法测定血清炎性因子(TNF-α、IL-6)和神经体液因子(BNP、AngII、ET-1)的变化。将动物模型随机分为HF组、HF+EGFP组、HF+SERCA2a组,并设假手术组作为对照,每组各4只。HF+EGFP组和HF+SERCA2a组再次开胸,心肌组织内注射包含报告基因的rAAV1-EGFP和包含靶基因的rAAV1-SERCA2a各1ml(1×1012v.g/ml)。基因转导60d后,处死各组动物,行免疫组化和Western blotting检测SERCA2a在心肌中的表达情况;超声心动和血流动力学检测转导SERCA2a对心功能的影响,并用放免法检测上述炎性因子和神经体液因子的变化。结果成功建立小型猪慢性心肌缺血HF模型12只,Ameroid环植入4周后,超声心动和血流动力学数据提示模型组心脏舒缩功能显著下降(P<0.05),并伴有外周血上述炎性因子和神经体液因子的激活。基因转导后60d,SERCA2a蛋白在HF+SERCA2a组的表达量显著高于HF及HF+EGFP组(P<0.05),但与对照组比较无显著差异;其心功能参数LVEF、Ev/Av、±dp/dtmax较HF及HF+EGFP组显著增高(P<0.05),并伴随血清炎性因子和神经体液因子浓度的明显下降(P<0.05),提示心功能好转,心衰严重程度下降。结论过表达SERCA2a可改善慢性缺血性心力衰竭的心脏功能,可能成为慢性心肌缺血、心力衰竭治疗的潜在手段。
Objective To study the effect of over-expression of cardiac sarcoplasmic reticulum Ca2 + -ATPase (SERCA2a) on cardiac function in chronic ischemic heart failure (HF) minipig. Methods Ameroid was used to narrow the initial segment of anterior descending descending coronary artery of miniature pigs. Four weeks later, the heart function was determined by echocardiography and hemodynamics. Serum inflammatory cytokines (TNF-α, IL-6) and nerve Changes of humoral factors (BNP, AngII, ET-1). The animal model was randomly divided into HF group, HF + EGFP group, HF + SERCA2a group, and sham-operated group as control group with 4 rats in each group. The HF + EGFP group and the HF + SERCA2a group were re-opened. The myocardium was injected with 1 ml each of rAAV1-EGFP containing the reporter gene and rAAV1-SERCA2a containing the target gene (1 × 1012 v.g / ml). Sixty days after gene transduction, all animals were sacrificed and the expression of SERCA2a in myocardium was detected by immunohistochemistry and Western blotting. The effect of SERCA2a transduction on cardiac function was detected by echocardiography and hemodynamics. Sexual factors and changes in neurohumoral factors. Results 12 HF models of miniature pig chronic myocardial ischemia were successfully established. After 4 weeks of Ameroid ring implantation, the data of echocardiography and hemodynamics showed that the systolic and diastolic function of model group was significantly decreased (P <0.05) Activation of the above inflammatory and neurohumoral factors. At 60 days after gene transduction, the expression of SERCA2a protein in HF + SERCA2a group was significantly higher than that in HF and HF + EGFP groups (P <0.05), but not significantly different from that in control group. The cardiac function parameters LVEF, Ev / Av, ± dp / dtmax was significantly higher than that in HF and HF + EGFP groups (P <0.05), accompanied by a significant decrease of serum inflammatory cytokines and neurohumoral factors (P <0.05), suggesting that heart function improved and the severity of heart failure decreased. Conclusion Overexpression of SERCA2a can improve cardiac function in patients with chronic ischemic heart failure and may be a potential treatment for chronic myocardial ischemia and heart failure.