Human Neural Stem Cells And Human Umbilical Cord Blood Stem Cell Transplantation In The Treatment Of Cerebral Ischemia In Experimental Research

Objective: To study the growth characterization and differentiation of neural stem cells from human embryonic cerebral tissue in vitro, then explore the effect of the human neural stem cells (hNSCs) transplantation to treat cerebral ischemic rats and the status of transplanted hNSCs in the ischemic brain tissue of these rats.Materials and Methods: Human neural stem cells were separated from 10-13 weeks brains of human embryo and were cultured and induced to differentiate.The middle cerebral artery occlusion rat models were made and the human neural stem cells were transplanted into the tail vein 1 day later.The Neurological Severity Scores(NSS) tests were undertaken in all the four groups 0-35 days after transplantation. Iimmunohistochemistry method was used to check the differentiation and migration of human neural stem cells in vitro and vivo.Results: Neural stem cells from human embryonic brains had been successfully cultured.It was found that they formed typical neurospheres in suspension,and the majority of the cells expressed nestin ,which wasthe marker for neural stem cells. 21 days later,the neurologic function of rats that received transplantation recovered much better than the rats that not received transplantation,as evidenced by the NSS(p<0.05).Within the brain tissue , Brdu reactive hNSCs were distributed throughout the damaged brain of recipient rats, the vast majority of cells localized to the ischemic hemisphere,few cells were observed in the contralateral hemisphere (p<0.05).Significantly more Brdu reactive cells were found in the brain tissue at the 21, 28 and 35 days respectively than in the brain tissue that at the 14 days after transpiantation (p<0.05). Nestin reactive cells were found within the damaged brains at every time point.Among all the Brdu reactive cells ,71.9%-73.8% were reactive for the astrocyte marker glial flbrillary acidic protein(GFAP), 16.7%—19.8% were reactive for the CNPase and 8.3%-9.5% expressed the neuronal markers neuron specific enolase(NSE). There was no statistical difference in NSS and immunohistochemistery between the rats that received transplantation 24 hours and 7 days after MACO.Conclusions: Human neural stem cells intravenous transplantation could effectively improve the neurologic function of rats.These cells had multipotential differentiation properties in vitro and vivo and the transplanted cells differentiated into three main types of neural cells by the influcence of the ischemic microenvironmental signals.