不同孕周人脐带间充质干细胞移植改善心肌梗死模型心脏功能的比较

Transplantation of human umbilical cord mesenchymal stem cells derived at different gestational weeks improves heart function in myocardial infarction models

BACKGROUND: Stem cells have multi-directional differentiation and self-replication abilities, under certain conditions, which can differentiate into myocardial cells to repair the damaged myocardium.OBJECTIVE: To investigate the effects of transplantation of umbilical cord mesenchymal stem cells derived at different gestational weeks on infarct size and angiogenesis in the infarct region of experimental rabbits with myocardial infarction.METHODS: Ten full-term umbilical cord samples and 10 umbilical cord samples of aborted fetuses at 10-12 gestation weeks were selected to in vitro isolate umbilical cord mesenchymal stem cells that were subjected to BrdU labeling. HLA-G expression was detected in the cells. Thirty white rabbits were selected to make myocardial infarction models, and 2 weeks after modeling, the model rabbits were randomized into aborted cell transplantation group, full-term cell transplantation group and control group (n=10 per group). Then, BrdU-labeled cells were injected correspondingly into the infarct region of rabbits in the two cell transplantation groups. Rabbits in the control group were subjected to an equal volume of serum-free. Four weeks after transplantation, heart function of rabbits was monitored using electrocardiogram, and myocardial tissues were taken to measure infarct size and blood capillary density. RESULTS AND CONCLUSION: HLA-G expression was different in different sources of umbilical cord mesenchymal stem cells: high HLA-G expression was found in the aborted umbilical cord mesenchymal stem cells, and meanwhile, low HLA-G expression was found in the full-term umbilical cord mesenchymal stem cells. Compared with the control group, the left ventricular end-diastolic volume and left ventricular ejection fraction of aborted and full-term cell transplantation groups were significantly improved, especially in the aborted cell transplantation group (P < 0.05). BrdU-positive cells were found in the infarct site in both transplantation groups. Compared with the control group, the infarct size and capillary density were improved most significantly in the aborted cell transplantation group followed by the full-term cell transplantation group (P < 0.05). Electrocardiogram findings showed significant improvement in both cell transplantation groups compared with the control group (P < 0.05), especially in the aborted cell transplantation group. These findings indicate that umbilical cord mesenchymal stem cells derived at low gestational weeks improve the heart function more significantly than the full-term umbilical cord mesenchymal stem cells, which have the potential to become a better source of cardiomyocytes for transplantation.