脐血MSCs移植对心肌梗死区旁残存心肌组织的影响

目的研究脐血间充质干细胞(MSCs)移植对心肌梗死区域旁残存心肌组织的影响。方法自孕犬脐血中分离、培养MSCs,经Laz基因转染和5-氮胞苷体外肌源性诱导后移植入犬急性心肌梗死模型(移植组,n=18)。分别于移植后1、4、8周处死动物,取心肌组织标本行TUNEL染色观察残存细胞凋亡情况并计算凋亡指数;应用激光共聚焦扫描显微镜图像分析系统检测残存心肌细胞体积;Nagar-Olsen染色观察心肌胶原网络的变化。以等量生理盐水注射作为移植对照组(n=18)。结果与对照组比较,移植组缺血区部各时间点切片位观察到凋亡细胞数目显著减少,凋亡指数明显降低;残存心肌细胞肥大明显;移植后第8周,心肌组织内胶原纤维排列整齐、规律。结论脐血MSCs移植可通过减少心肌细胞凋亡、促使残存心肌细胞肥大、调节心肌胶原网络而改善心功能。

Influence of umbilical cord blood mesenchymal stem cells transplantation on remnant myocardium after acute myocardial infarction

Objective To investigate the influence of umbilical cord blood mesenchymal stem cells(MSCs) transplantation on remnant myocardium after acute myocardial infarction. Methods MSCs were harvested,cultured and expanded from umbilical cord blood of pregnant canine. MSCs were transplanted into the canine model of acute myocardial infarction that was labeled by Lac and differentiated by 5-azacytidine (transplantation group, n=18). The animals were sacrificed after 1,4 and 8 weeks, and specimens were detected by TUNEL for apoptosis of myocardium and apoptotic index, confocal microscopy for myocardial cell volume, and Nagar-Olsen staining for myocardial collagen network. The control group was established by injection of physiologic saline (n=18). Results With comparision to the control group, the number of apoptotic cells and apoptotic index were significantly decreased in the ischemic region of the transplantation group, the hypertrophy of remnant myocardium was more obvious, and the collagen fibers lined up in order with less fusion after 8 weeks. Conclusion Transplantation of MSCs can improve the cardiac function by decrease of myocardial apoptosis, induction of hypertrophy and modulation of myocardial collagen network after myocardial infarction.