脐血源性神经干细胞移植对缺血缺氧性脑损伤新生大鼠的治疗作用

Therapeutical effects of transplantation of neural stem cells from human umbilical cord blood on neonatal rats with hypoxic-ischemia brain damage

目的探讨人脐血源性神经干细胞(NSCs)移植治疗缺血缺氧性脑损伤(HIBD)新生大鼠的可行性。方法 7 d龄大鼠随机分成NSCs移植(A)组、HIBD模型对照(B)组和正常对照(C)组,每组40只。从人脐血中分离出单个核细胞(UBC-MNCs),定向诱导分化出NSCs并行溴脱氧核苷尿嘧啶(BrdU)标记,经尾静脉移植到HIBD新生大鼠体内。免疫组化法检测移植后1、7、142、1 d各组动物脑组织易损区室管膜前下区(SVZa)神经巢蛋白(Nestin)、神经元特异性烯醇酶(NSE)、胶质纤维酸性蛋白(GFAP)、BrdU染色阳性细胞表达情况及移植细胞在脑内的存活、迁移和分化情况。结果 UBC-MNCs可体外培养并定向诱导分化为NSCs,A组SVZa区NSE、BrdU阳性细胞表达量较B组均增高(P<0.01);移植早期Nestin增高,移植后14 d达峰,以后逐渐下降(P<0.01);A组GFAP表达较B组降低,大鼠损伤区面积显著减小(P<0.01)。结论移植的NSCs可在HIBD新生大鼠SVZa存活、增殖及分化,促进组织结构恢复和细胞功能重建,NSCs移植是治疗HIBD的一种新途径。

Objective：To investigate the feasibility of the cell intravenous transplantation of neural stem cells（NSCs） from human umbilical cord blood in treating hypoxic-ischemia brain damage（HIBD） in neonatal rats.Methods：Rats aged 7 days old were divided randomly into three groups of A（NSCs transplantation）,B（HIBD model） and C（normal control） with 40 rats each.The MNCs were isolated from human umbilical cord blood and cultured in neurobasal medium adding with hEGF,bFGF and B27 factures in vitro.The UBC-MNCs were induced and differentiated into NSCs.Target cells were traced by BrdU.The NSCs were injected intravenously into neonatal HIBD rats.The expressions of nestin,NSE,GFAP,BrdU positive cells in SVZa areas and survival,migration and differentiation of the NSCs were observed by immunohistochemistry.Results：UBC-MNCs could differentiate into neuron-like cells after orientationally induced.The expressions of NSE and BrdU positive cells in SVZa areas were significantly higher in group A than those in group B（P0.01）.The expresstion of nestin increased early after transplantation,peaked on the 14th day,and then gradually decreased.The expression of GFAP in group A was lower than that in group B with reduced damage areas（P0.01）.Conclusion：The transplanted NSCs may survive,differentiate and migrate in brain SVZa,which promotes the rehabilitation of organ structure and reconstruction of cell functions.NSCs transplantation is a new approach for the treatment of HIBD.