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目的 本研究的目的是在大鼠心梗模型中,应用诱导多能干细胞(iPSC)分化的心肌细胞(iPSC-CMs)移植,研究iPSC-CMs移植对心梗的修复及心功能改善的作用机制.方法 结扎鼠冠状动脉前降支制作心肌梗死(MI)模型,分别在心梗及心梗边缘区注射总量30ul 4×105 iPS-CMs(iPS-CMs组)和等量的PBS(MI组).细胞移植后4周应用心脏超声评价心脏功能改变,TUNEL法检测心肌细胞凋亡,ELISA分析细胞移植后的促血管生成蛋白的表达.结果 心脏超声结果显示移植4周后,与MI组相比,iPS-CMs组左心室射血分数改善明显(LVEF,52.7±4.52％ vs 41.82±6.31％,n=8,P＜0.05),并且心肌细胞凋亡率显著下降(29.33±9.86％ vs 44.63±10.25％,P＜0.05).ELISA结果显示iPS-CMs组可以促进血管生成素蛋白(angiopoietin-1)和血管内皮生长因子(VEGF)的表达.结论 iPS-CMs移植治疗心梗可以改善心脏功能,其机制是抑制自体心肌细胞的凋亡以及调控促血管生成蛋白的表达.“,”Objective The purpose of this study is to investigate the mechanism of heart function improvement using human induced pluripotent stem cells(iPSC-CMs) for myocardial repair in a rat model of myocardial infarction (MI).Methods Animals induced with MI model by LAD ligation were randomly assigned to receive direct intramyocardial injection of 4× 105 iPS-CMs (iPS-CMs group) or PBS (MI group) at the infarct and border zone.The heart function changes,myocardial cell apoptosis and proangiogenic proteins expression was evaluated 4 weeks after iPS-CMs transplantation.Results The LVEF was significantly increased and native cardiomyocytes apoptosis was significantly reduced in iPS-CMs group compared with the MI group (52.7 ± 4.52％ vs 41.82 ± 6.31％,and 29.33±9.86％ vs 44.63±10.25％,n=8,P＜0.05) 4 weeks after cell transplantation.ELISA result showed iPS-CMs transplantation can upgrade the expression of angiopoietin-1 protein and vascular endothelial growth factor (VEGF).Conclusion Our results suggest that transplantation of iPSC-CMs can improve the heart function via restrain the native cardiomyocytes apoptosis and upgrade the expression of the proangiogenic proteins after transplantation in MI rat models.