Subregional Specification of Embryonic Stem Cell-Derived Ventral Telencephalic Tissues by Timed and Combinatory Treatment with Extrinsic Signals
Subregional Specification of Embryonic Stem Cell-Derived Ventral Telencephalic Tissues by Timed and Combinatory Treatment with Extrinsic Signals
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DOI：
10.1523/jneurosci.5128-10.2011
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发表时间：
2011-02-02
影响因子：
5.3
通讯作者：
Sasai, Yoshiki
中科院分区：
文献类型：
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作者：
Danjo, Teruko;Eiraku, Mototsugu;Sasai, Yoshiki
在端脑早期发育过程中，腹侧端脑（基底神经节隆起下区）的主要部分被细分为三个区域，即外侧（LGE）、内侧（MGE）和尾侧（CGE）神经节隆起。在这项研究中，我们在小鼠胚胎干细胞（ESC）培养中系统地重现了基底神经节隆起下区的模式形成，并研究了模式形成信号的时间和组合作用。在无血清悬浮培养中， Sonic hedgehog（Shh）信号以剂量依赖的方式决定了ESC衍生的端脑神经外胚层的背腹分化。早期的Shh处理，甚至在Foxg1（也是Bf1；端脑谱系的最早标志物）表达开始之前，对于高效产生LGE祖细胞至关重要，并且持续的Shh信号直到第9天对于使这些细胞定向分化为LGE谱系是必要的。当在这些条件下诱导并通过荧光激活细胞分选仪纯化后，端脑细胞高效分化为Nolz1（+）/Ctip2（+）LGE神经元前体细胞，随后，在培养中和体内移植后，都分化为DARPP32（+）中等大小的棘状神经元。用高剂量的Hedgehog（Hh）激动剂SAG（Smoothened激动剂）处理的纯化端脑祖细胞分化为类似MGE和CGE的组织。有趣的是，除了强烈的Hh信号外，MGE细胞的有效分化还需要Fgf8信号，但会被Fgf15/19处理所抑制。相反，CGE分化被Fgf15/19促进但被Fgf8抑制，这表明特定的Fgf信号在ESC衍生的腹侧基底神经节隆起下区组织的位置分化中起着不同的关键作用。我们讨论了一个关于Fgf8和Fgf15/19信号在头侧 - 尾侧基底神经节隆起下区模式形成中拮抗作用的模型，并将其与这些分子在皮质模式形成中的作用进行了比较。
During early telencephalic development, the major portion of the ventral telencephalic (subpallial) region becomes subdivided into three regions, the lateral (LGE), medial (MGE), and caudal (CGE) ganglionic eminences. In this study, we systematically recapitulated subpallial patterning in mouse embryonic stem cell (ESC) cultures and investigated temporal and combinatory actions of patterning signals. In serum-free floating culture, the dorsal-ventral specification of ESC-derived telencephalic neuroectoderm is dose-dependently directed by Sonic hedgehog (Shh) signaling. Early Shh treatment, even before the expression onset of Foxg1 (also Bf1; earliest marker of the telencephalic lineage), is critical for efficiently generating LGE progenitors, and continuous Shh signaling until day 9 is necessary to commit these cells to the LGE lineage. When induced under these conditions and purified by fluorescence-activated cell sorter, telencephalic cells efficiently differentiated into Nolz1(+)/Ctip2(+) LGE neuronal precursors and subsequently, both in culture and after in vivo grafting, into DARPP32(+) medium-sized spiny neurons. Purified telencephalic progenitors treated with high doses of the Hedgehog (Hh) agonist SAG (Smoothened agonist) differentiated into MGE- and CGE-like tissues. Interestingly, in addition to strong Hh signaling, the efficient specification of MGE cells requires Fgf8 signaling but is inhibited by treatment with Fgf15/19. In contrast, CGE differentiation is promoted by Fgf15/19 but suppressed by Fgf8, suggesting that specific Fgf signals play different, critical roles in the positional specification of ESC-derived ventral subpallial tissues. We discuss a model of the antagonistic Fgf8 and Fgf15/19 signaling in rostral-caudal subpallial patterning and compare it with the roles of these molecules in cortical patterning.