大鼠视神经损伤后移植人胚胎神经干细胞的实验研究

Experimental study on transplantation of human hippocampus-derived neural stem cells in optic nerve injury rat

目的探讨异种神经干细胞注射到玻璃体腔后迁移到视网膜的存活及分化,为进一步研究重建视觉传导通路奠定基础。方法在近SD大鼠眼球后壁夹住视神经根部5min,造成视神经损伤,将起源于人胚胎大脑海马的神经干细胞悬浮液注射到SD大鼠的玻璃体腔中。移植的神经干细胞预先用荧光染料Hoechst标记。分别于手术后不同的时间处死,剥离出视网膜,进行免疫组织化学染色,在荧光显微镜下观察实验结果。结果宿主视网膜在荧光显微镜下可见Hoechst标记阳性的移植细胞,移植前移植细胞神经胶质原纤维酸蛋白(GFAP)阳性表达的,移植后为阴性表达。结论视神经损伤大鼠的玻璃体腔内注射起源于人胚胎大脑海马的神经干细胞,移植细胞可以迁移到视网膜组织中存活。

Objective To explore the survival and differentiation of heterogeneity neural stem cells（human hippocampusderived neural stem cells） in retina after human hippocampus-derived neural stem cells are injected into vitreous space. Methods Twenty-eight adult rats were assigned to four groups randomly. Mechanical injury was induced in the optic nerve of SD rat by clamping the optic tract for 5 minutes. Human hippocampus-derived neural stem cells were marked with Hoechst 33342. Stem cells suspension was slowly injected into the vitreous space in the experimental rats. Retina of adult rat was processed for immunohistochemical studies at the lst,2nd,4th and 7th week after the stem cells transplantation. Results In the 1 st,2nd,4th and 7th week,blue Hoechst marked cells（ grafted stem cells）were seen on the host retina. In week 1 after transplantation, some grafted stem cells were seen in the rat retina, and the peak time of grafted stem cells incorporation into rat retina was the 2nd week after transplantation. Before the transplantation, the stem cells showed positive-immunoreactivity for GFAP. The around retina of grafted stem cells had a high expression level for GFAP,but the all grafted stem cells did not expressed GFAP in the 7th week. Conclusion In optic nerve injury rat, the incorporation of the grafted stem cells into retina can be achieved by injecting the human hippocampus-derived neural stem cells into vitreous space.