移植的神经干细胞在脑损伤区壳聚糖载体中的存活与分化

目的:探讨移植的NSCs在大鼠脑损伤区壳聚糖载体中的存活、分化情况及其对TBI大鼠认知功能的影响。方法:低温冷冻干燥法制备壳聚糖多孔支架。将从鼠胚前脑中分离的NSCs扩增、标记BrdU。Feeney法制备SD大鼠TBI模型,随机分为3组:损伤对照组清创后不做移植;NSCs 支架移植组行壳聚糖作载体的NSCs移植;NSCs 支架 NGF移植组行壳聚糖作载体的NSCs移植,并在其中加入NGF。术后1、2、3个月行避暗回避和跳台试验。脑切片行Nissl染色、BrdU与NF-200免疫荧光双标染色。结果:两移植组的认知功能在术后1、2、3个月较损伤对照组明显改善,含NGF的移植组改善更加显著。两移植组术后1、2、3个月在移植区均可见BrdU与NF-200免疫荧光双标细胞,含NGF移植组中的双标细胞数量多、胞体大、突起多且长。结论:大鼠TBI后移植的外源性NSCs可以在脑损伤区壳聚糖载体中长期存活并向神经元分化,可以改善大鼠的认知功能;NGF对其具有促进作用。

Survival and differentiation of transplanted NSCs in the chitosan porous scaffold within the cerebral cortex lesion of rats

Objective: To explore the survival and differentiation of transplanted NSCs in the chitosan porous scaffold within the cerebral cortex lesion of rats and the influence on the cognitive function of rats with TBI. Methods: The porous chitosan scaffold was made by Freezing-drying technique. The NSCs coming from rat fetal forebrain were labeled with BrdU. Sprague-Dawley(SD) rats' TBI models were made by Feeney's method. The TBI rats were randomly divided into injury-control group, NSCs scaffold group and NSCs scaffold NGF group. The rats were immediately debrided after injury, then NSCs combined with the chitosan porous scaffold were transplanted into injured cerebral cortex in NSCs scaffold group, NSCs combined with the chitosan porous scaffold and NGF were transplanted into injured cerebral cortex in NSCs scaffold NGF group. Rats were tested for cognitive function using step-through and step-down test at 1, 2 and 3 months postop. Nissl staining and NF-200/BrdU double immunofluorescence were used for brain sections. Results: Significant improvement in cognitive function was observed after transplantation in two transplanting groups, and the cognitive function improvement of rats in NSCs scaffold NGF group was more obvious than that of rats in NSCs scaffold group. NF-200 and BrdU double-labeled cells were detected in the transplantation zone of two transplanting groups at 1, 2 and 3 months postop. The number of BrdU and NF-200 double-labeled cells with more and longer processes in NSCs scaffold NGF group was more than that in NSCs scaffold group. Conclusions: Transplanted NSCs can survive for long time and differentiate into neurons in the chitosan porous scaffold within the cerebral cortex lesion of rats with TBI, which can improve the cognitive function of rats. Ectogenic NGF can accelerate all these changes.