Intracerebral transplantation of human erythropoietin gene-modified mesenchymal stem cells derived from human umbilical cord blood alleviates hypoxic ischemic brain injury in neonatal rats

Objective To investigate the therapeutic effect of intracerebral transplantation of human erythropoietin (EPO) gene-modified mesenchymal stem cells (MSCs) derived from human umbilical cord blood (UCB) on hypoxic-ischemic brain damage (HIBD) in neonatal rats.Methods MSCs were isolated from human UCB by density gradient centrifugation,and identified by flow cytometry (FCM). pcDNA3-EPO was introduced into the human UCB-derived MSCs by lipofectamine and the expression of exogenous EPO was examined by RT-PCR and Western blot. Forty-two 7-day-old SD rats with HIBD were divided into 3 groups:control group (A group,n = 12),MSCs transplant group (B group,n = 12),and EPO gene-modified MSCs transplant group(C group,n = 18). On the 3rd day after HIBD,MSCs were injected into the left cortex of neonatal rats. Seven days after transplantation,6 rats of C group were sacrificed to investigated the survival and migration of the transplanted cells by immunohistochemtry. On the 1st,7th,14th,21st and 28th days after transplantation,nervous function of 3 groups were evaluated by modified neurological severity score (mNSS). Results MSCs were isolated from full-term newborn UCB. FACS analysis showed that MSCs were positive for CD29,CD44,and CD105 and negative for CD34,CD106,and HLA-DR. The results of RT-PCR and Western blot analyses indicated that the exogenous EPO could be successfully expressed in human UCB-derived MSCs. Immunocytochemistry analysis of brain tissue sections showed that the transplanted human UCB-derived MSCs could survive and migrate around from the center of transplant site. mNSS showed that the score of C group was significantly smaller than control group on the 14th,21st,and 28th days (P 0.05 or P 0.01),and mNSS of B group was significantly smaller than control group on the 21st and 28th days (P 0.05). Compared with B group,the score of C group was significantly smaller on the 21st and 28th day(P 0.05). Conclusion Transplantation of EPO gene-modified MSCs is effective to treat neonatal rat HIBD.