Gao Limin, Miller Robert H
Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio 44106, USA.
J Neurosci. 2006 Jul 19;26(29):7619-28. doi: 10.1523/JNEUROSCI.0855-06.2006.
Cell fate commitment in the developing CNS frequently depends on localized cell-cell interactions. In the avian visual system the optic nerve oligodendrocytes are derived from founder cells located at the floor of the third ventricle. Here we show that the induction of these founder cells is directly dependent on signaling from the retinal ganglion cell (RGC) axons. The appearance of oligodendrocyte precursor cells (OPCs) correlates with the projection of RGC axons, and early eye removal dramatically reduces the number of OPCs. In vitro signaling from retinal neurites induces OPCs in responsive tissue. Retinal axon induction of OPCs is dependent on sonic hedgehog (Shh) and neuregulin signaling, and the inhibition of either signal reduces OPC induction in vivo and in vitro. The dependence of OPCs on retinal axonal cues appears to be a common phenomenon, because ocular retardation (or(J)) mice lacking optic nerve have dramatically reduced OPCs in the midline of the third ventricle.
在发育中的中枢神经系统中，细胞命运的决定通常依赖于局部的细胞间相互作用。在鸟类视觉系统中，视神经少突胶质细胞源自位于第三脑室底部的起始细胞。在此我们表明，这些起始细胞的诱导直接依赖于视网膜神经节细胞（RGC）轴突发出的信号。少突胶质细胞前体细胞（OPC）的出现与RGC轴突的投射相关，早期摘除眼球会显著减少OPC的数量。来自视网膜神经突的体外信号可在反应性组织中诱导产生OPC。视网膜轴突对OPC的诱导依赖于音猬因子（Shh）和神经调节蛋白信号，抑制这两种信号中的任何一种都会降低体内和体外的OPC诱导。OPC对视神经轴突信号的依赖性似乎是一种普遍现象，因为缺乏视神经的眼发育迟缓（or(J)）小鼠在第三脑室中线处的OPC数量显著减少。
