Effect of Intracerebral Transplantation of Mesenchymal Stem Cells Derived from Human Umbilical Cord Blood on Hypoxic-Ischemic Brain Damage in Neonatal Rat

Objective To investigate the therapeutic effect of intracerebral transplantation of mesenchymal stem cells(MSCs) derived from human umbilical cord blood(UCB) on hypoxic-ischemic brain damage(HIBD) in neonatal rat.Methods Twenty samples of human UCB were collected from healthy full-term newborns.MSCs were isolated from human UCB by density gradient centrifugation and purified by adhere cell selection method.For transplantation,P3 human UCB-derived MSCs were labeled by the 5-bromo-2-deoxyuridine (BrdU).Thirty SD rats of 7 d were built for neonatal HIBD model.One rat died and others were divided into transplant group(n=18) and control group(n=11).At the third day after building models,human UCB-derived MSCs were injected into left cortex in transplant group,while PBS of the same volume was injected into the same site in control group at the same time.The seventh day after transplantation,6 rats of transplant group were sacrificed to prepare brain tissue sections.The survival,migration and differentiation of the transplanted cells were investigated by brain tissue immunohistochemical analysis,and nervous function of 2 groups were evaluated by modified neurological severity score(mNSS) on the first,7th,14th,21th and 28th day after transplantation.Results MSCs were isolated from 5 of 20 human UCB samples.Immunocytochemical analysis of brain tissue showed that the transplanted human UCB-derived MSCs could survive and migrate around by the center of transplant site.There were (12.67±2.73)% of MSCs differentiated into astrocyte-like cells.mNSS showed that the score of transplant group was lower than that of control group on the first,7th,14th,21th and 28th day,and the differences of score points between 2 groups on the 14th,21th and 28thday were statistically significant(Pa0.05).Conclusion It is effective for the transplantation of human UCB-derived MSCs to treat neonatal rat HIBD.