经bcl-2基因修饰的骨髓间充质干细胞移植对缺血性心功能不全兔心功能及血管新生的影响

目的:探讨经bcl-2基因修饰的骨髓间充质干细胞(BMSCs)移植对急性心肌梗死家兔心肌细胞凋亡、血管再生及心功能的影响。方法:体外分离、培养、纯化兔BMSCs,分别转染腺病毒及重组腺病毒-Bcl-2。结扎兔冠状动脉前降支制作心肌梗死(MI)模型,2周后于心梗边缘区分别注射等量的腺病毒-Bcl-2-BMSCs(MI+Bcl-2-BMSCs组)、腺病毒-BMSCs(MI+BMSCs组)及DMEM液(MI组)。细胞移植4周后经超声测定心功能;荧光显微镜观察BMSCs的存活及分布;TUNEL法检测心肌细胞凋亡;real-time PCR检测VEGF mRNA表达;免疫组化染色法检测CD31表达,计算新生毛细血管密度。以上数据分别与心功能进行相关性分析。结果:与MI组相比,MI+Bcl-2-BMSCs组和MI+BMSCs组的心功能改善、细胞凋亡率降低、VEGF mRNA表达增多、毛细血管密度增加,其中MI+Bcl-2-BMSCs组的变化更为显著(P0.05)。相关性分析显示左室射血分数与心肌细胞凋亡率呈负相关;与VEGF mRNA的表达量及毛细血管密度呈正相关(P0.01)。结论:经bcl-2基因修饰的BMSCs移植可显著减少缺血性心功能不全兔心肌细胞凋亡、促进血管再生、改善心功能。

Transplantation of bcl-2 gene-modified bone marrow mesenchymal stem cells improves cardiac function and angiogenesis in rabbit ischemic car-diac insufficiency model

AIM: To investigate the effects of transplantation of bone marrow mesenchymal stem cells (BMSCs) modified by bcl-2 gene on myocardial cell apoptosis, angiogenesis and cardiac function in the rabbit after acute myocardial infarction (MI).METHODS: The rabbit BMSCs were isolated, cultured and purified in vitro. The BMSCs were transfected with adenovirus or adenovirus-Bcl-2. The rabbit model of MI was established by ligation of left anterior descending branch. The rabbits were injected with Ad-Bcl-2-BMSCs (MI+Bcl-2-BMSCs group), Ad-BMSCs (MI+BMSCs group) and DMEM (MI group) in infarction marginal zone 2 weeks after ligation. The cardiac function was evaluated by echocardiography.The apoptosis of myocardial cells was measured by TUNEL. The mRNA expression of VEGF was detected by real-time PCR. The expression of CD31 was examined by immunohistochemical staining, and new blood capillaries were counted at 4 weeks after BMSCs transplantation. The correlation of the above values with cardiac function was analyzed.RESULTS: The cardiac function was better, the apoptotic rate was lower, the mRNA expression of VEGF and the capillary density were higher in both MI+Bcl-2-BMSCs group and the MI+BMSCs group than those in MI group, and those in MI+Bcl-2-BMSCs group increased more obviously.The left ventricular ejection fraction (LVEF) had a negative correlation with the myocardial cell apoptosis rate. A positive correlation with the mRNA expression level of VEGF and the capillary density was also observed.CONCLUSION: The transplantation of BMSCs modified by bcl-2 gene significantly reduces the myocardial cell apoptosis, promotes angiogenesis, improves heart function of the rabbits with MI.