人牙源性iPSCs分化心肌细胞促进急性心肌梗死小鼠心肌修复的研究

The effect of cardiomyocytes derived from human dental-origin iPSCs on cardiac repair in murine model of acute myocardial infarction

目的探讨人牙源性诱导性多能干细胞(iPSCs)分化心肌细胞对急性心肌梗死(AMI)小鼠心功能的影响。方法采用仙台病毒诱导、单克隆挑选和无饲养层体系将人牙根尖乳头干细胞(SCAP)重编程为iPSCs,心肌分化培养基定向诱导。9只BALB/C雄性小鼠按照随机数字表法分为正常组(不干预)、AMI组(AMI造模)和实验组(AMI造模+iPSCs-CMs注射),每组3只。通过冠状动脉结扎法建立急性心肌梗死小鼠模型,iPS分化心肌细胞行心肌内局部注射,超声心动图评估心脏功能。结果人SCAP-iPSCs呈现典型胚胎干细胞样克隆形态,体内具备多向分化潜能,分化心肌细胞具有自主搏动性,表达特异性标志物α-辅肌动蛋白(α-actinin)和肌钙蛋白T(TNNT-2)。术后即刻心电图和超声心动图证实AMI模型成功。与正常组相比,AMI组左心室短轴缩短率(LVFS)和左心室射血分数(LVEF)明显下降,实验组LVFS和LVEF显著高于AMI组(P<0.05)。结论人牙源性iPSCs分化心肌细胞局部注射可以明显改善AMI小鼠的心功能,促进心肌修复。

Objective To investigate the effect of myocardial cells differentiated from human SCAP-induced pluripotent stem cells(iPSCs)on the myocardial function of acute myocardial infarction(AMI)mice.Methods Human stem cells from apical papilla(SCAP)was reprogrammed to iPSCs with Sendai reprogramming kit and passed using single colony subcloning under feeder-free condition.Specific myocardial differentiation medium was utilized to induce iPSCs.Nine BALB/C male mice were divided into the normal group(no intervention),the AMI group(AMI modeling)and the experimental group(AMI modeling+iPSCs-CMs injection)using random number table method.AMI mice model was established by coronary artery ligation.The derived cardiomyocytes(CMs)were injected into peri-infarct region of mice,and myocardial function was accessed by echocardiography.Results The derived iPSCs exhibited morphology resembling with embryonic stem cells(ESCs)and formed three-germ layers in nude mice.The CMs were able to beat independently and expressed specific markers,α-actinin and TNNT-2.The success of AMI model was confirmed by immediate electrocardiogram after operation.Compared with the normal group,LVFS and LVEF decreased significantly in the AMI group,and LVFS and LVEF were significantly higher in the experimental group than those in the AMI group(P<0.05).Conclusion Local injection of human odontogenic iPSCs differentiated cardiomyocytes can significantly improve the cardiac function and promote myocardial repair in AMI mice.