调控Smo活性对成年大鼠神经干细胞增殖和迁移的影响

目的 探讨Shh信号通路中G蛋白偶联受体Smoothened（Smo）对成年大鼠神经干细胞（ANSCs）增殖、迁移的影响并阐明其作用机制。方法 培养ANSCs，分别添加Smo的激动剂Purmorphamine及其抑制剂Cyclopamine，细胞增殖-毒性实验（CCK8）检测其对ANSCs增殖的影响；细胞划痕实验检测其对ANSCs迁移能力的影响；实时荧光定量PCR（RT-PCR）技术检测Sonic Hedgehog（Shh）信号通路的细胞表面Patched蛋白（Ptch1）、G蛋白偶联受体Smo、转录因子（Gli1）以及神经导向因子（Slit1）和脑源性神经营养因子（BDNF）表达量的变化。结果 Smo激动剂PM对ANSCs的增殖有明显促进作用，48 h后PM组ANSCs的吸光度明显升高（P<0.01）；PM可以促进ANSCs的迁移，48 h后的PM组ANSCs划痕面积显著减小（P<0.01）；Smo抑制剂CPM对ANSCs的增殖和迁移均有显著的抑制作用；RT-PCR实验显示PM组细胞中的Ptch1、Smo、Gli1及Slit1、BDNF表达水平均明显增加（P<0.05）。结论 调控Smo的活性可以促进或抑制成年神经干细胞的增殖和迁移，其作用机制可能与调节BDNF和Slit1的表达有关。

G-protein coupled receptor Smo positively regulates proliferation and migration of adult neural stem cells in vitro

Objective To investigate the role of G-protein coupled receptor Smoothened (Smo) in regulating proliferation and migration of adult neural stem cells (ANSCs) and explore the underlying mechanism. Methods Cultured ANSCs were treated with purmorphamine (PM, an agonist of Smo) or cyclopamine (CPM, an inhibitor of Smo), and the changes in cell proliferation migration abilities were assessed using cell counting kit-8 (CCK8) assay and wound healing assay, respectively. The mRNA expressions of membrane receptor Patched 1 (Ptch1), Smo, glioma-associated oncogene homolog 1 (Gli1), axon guidance cue slit1 (Slit1) and brain-derived neurotrophic factor (BDNF) in the treated cells were detected using real-time quantitative PCR (RT-PCR). Results PM significantly promoted the proliferation (P<0.01) and migration of ANSCs (P<0.01), and up-regulated the mRNA expressions of Ptch1, Smo, Gli1, Slit1 and BDNF. Treatment with CPM significantly inhibited the proliferation and migration of ANSCs. Conclusion Modulating Smo activity can positively regulate the proliferation and migration of ANSCs possibly by regulating the expressions of BDNF and Slit1.