Transplantation of human umbilical cord mesenchymal stem cells at different gestational age for myocardium revascularization after myocardial infarction / 中国组织工程研究

ABSTRACT

BACKGROUND:Transplantation of stem cells has a beneficial effect on myocardium revascularization and improving cardiac function after myocardial infarction, and HLA-G protein contributes to the formation and maintenance of the immune tolerance. OBJECTIVE:To investigate the transplantation effects of human umbilical cord mesenchymal stem cells at different gestational age with different HLA-G expression levels on myocardium revascularization after myocardial infarction in rabbits. METHODS:Thirty healthy New Zealand rabbits were selected and were randomly divided into human smal gestational age umbilical cord-derived mesenchymal stem cells transplantation group, human ful-term umbilical cord-derived mesenchymal stem cells transplantation group and control group. After the rabbits models of acute myocardial infarction had been established, the former two groups were infused different umbilical cord-derived human umbilical cord mesenchymal stem cells labeled with 5-bromo-2-deoxyuridine into the edge and center of myocardial infarct region by multipoint injection. Rabbits in the control group were subjected to an equal volume of serum-free culture medium. RESULTS AND CONCLUSION:Four weeks after celltransplantation, 5-bromo-2-deoxyuridine-positive cells were found surrounding the infarct site in both transplantation groups. Myocardial fibrosis and myocardial infarct size were significantly lower in both transplantation groups than those of the control group (P<0.05), and there was a significant difference between the two transplantation groups (P<0.01). The positive staining of factor VII indicated that capil ary density was increased significantly in the smal gestational age umbilical cord-derived mesenchymal stem cells transplantation group as compared with the ful-term umbilical cord-derived mesenchymal stem cells transplantation group (P<0.01), and a sstatistical difference was found between two transplantation groups and the control group (P<0.01). Transplantation of human umbilical cord mesenchymal stem cells with high HLA-G expression increases new capil ary vessels and improves myocardium revascularization. Al indicate that human smal gestational age umbilical cord mesenchymal stem cells have the potential to become the better source of cardiomyocytes transplantation.