施万细胞对植入大鼠脊髓损伤区内的神经干细胞存活和分化的影响

目的 探讨施万细胞对植入损伤脊髓内的神经干细胞的存活及其分化的影响。方法 分离和克隆新生大鼠海马组织的神经干细胞;同时获取坐骨神经和臂丛神经,从中分离和纯化施万细胞。在移植前先用核荧光(Hoechst33342)标记神经干细胞。实验组为神经干细胞和施万细胞联合移植入大鼠脊髓半横断处,对照组为单独神经干细胞移植。应用免疫组织化学和酶组织化学技术,在移植后7d、14d、21d和30d分别观察神经干细胞的存活和分化情况。结果 实验组的神经干细胞比对照组迁移的更远,分化为神经丝蛋白染色阳性神经元样细胞的数量比对照组的多,并且有较长的突起长出。在30d实验组中,移植的神经干细胞有部分呈乙酰胆碱酯酶(AchE)染色阳性。而在对照组中,移植区内仅有少数呈AchE染色弱阳性的神经干细胞。结论 在脊髓损伤处,施万细胞可促进移植的神经干细胞存活、迁移和向神经元样细胞分化;有些神经元样细胞能长出较长的突起,有些呈现乙酰胆碱酯酶活性。

EFFECTS OF SCHWANN CELLS ON SURVIVAL AND DIFFERENTIATION OF NEURAL STEM CELLS TRANSPLANTED INTO INJURED SPINAL CORD

Objective To explore whether Schwann cells could promote the survival and differentiation of neural stem cells as they transplanted into injured spinal cord. Methods Neural stem cells were dissociated and cloned from the hippocampus of newborn rats.Schwann cells were also dissociated and purified simultaneously from the sciatic nerves and brachial plexus nerves of newborn rats.Before grafted,neural stem cells were prelabeled by nuclear fluorescent(Hoechst33342).In the experimental group,neural stem cells and Schwann cells were transplanted into the hemisection site of spinal cord of rats.However,only neural stem cells were transplanted in the control group.At 7d,14d,21d and 30d respectively after operated,we observed the survival and differentiation of neural stem cells transplanted into injured spinal cord with immunohistochemistry and enzymehistochemistry. Results In experimental groups neural stem cells migrated longer than those in control groups.The numbers of differentiated NF-positive neuron-like cells in experimental groups were more than those in control groups.We observed that some NF-positive cells grew longer processes.In the 30d groups,some of neural stem cells expressed AchE activity at the lesion site of spinal cord in the experimental group;a few of neural stem cells expressed AchE activity in the lesion site in the control group.Conclusion Schwann cells can promote the survival,migration and differentiation of transplanted neural stem cells.Differentiated neuron-like cells have longer processes and expressed AchE activity.