巨噬细胞促进神经干细胞向小鼠脊髓损伤区迁移

Macrophages promote the migration of neural stem cells into mouse spinal cord injury site

目的探讨巨噬细胞在神经干细胞(NSC)体内和体外迁移中的作用。方法体外分离、培养携带绿色荧光蛋白(GFP)小鼠的NSC,免疫荧光细胞化学染色检测神经上皮干细胞蛋白(nestin)表达;制作小鼠脊髓损伤模型,利用实时定量PCR检测组织巨噬细胞趋化蛋白1(MCP-1)mRNA水平,在损伤区两侧局部微量注射携带GFP的NSC,于1周后观察NSC向损伤区迁移情况;体外培养巨噬细胞,用TranswellTM迁移实验检测其对NSC迁移的影响,用ELISA检测MCP-1的含量。结果获得高表达nestin的NSC;与对照组相比,脊髓损伤组脊髓MCP-1 mRNA水平显著升高,注射入脊髓的NSC自注射区向损伤区迁移,并到达高表达F4/80区域。巨噬细胞可显著增加NSC体外迁移的数量,并分泌大量MCP-1。结论巨噬细胞诱导NSC向脊髓损伤区迁移,其可能机制是通过MCP-1起作用。

Objective To explore the role of macrophages in the migration of neural stem cells （NSCs） in vivo and in vitro. Methods NSCs with green fluorescent protein （GFP） were isolated from GFP transgenic mice and the cytochemical staining of nestin was used to identify NSCs. After spinal cord injury was induced, the tissue level of macrophage chemotactic protein-1 （ MCP-1 ） mRNA was detected using quantitative real time PCR. The migration of GFP- NSCs was investigated 1 week after GFP-NSCs were injected into both sides of the damaged area. The effect of macrophage on the migration of NSCs in vitro was tested by TranswellTM system and the content of MCP-1 was detected by ELISA. Results NSCs highly expressed nestin. Compared with the control group, the level of MCP-1 mRNA significantly increased in the spinal cord injury group. The NSCs which were injected into the spinal cord migrated into the center of the injured site where F4/80 was highly expressed. Macrophages significantly increased the number of migrating NSCs in vitro and the secretion of MCP-1. Conclusion Macrophages induce NSC migrating into the spinal cord injury site possibly through promoting the secretion of MCP-1.