Hasegawa Yuiko, Takata Nozomu, Okuda Satoru, Kawada Masako, Eiraku Mototsugu, Sasai Yoshiki
Laboratory for Organogenesis and Neurogenesis, RIKEN Center for Developmental Biology, 2-2-3, Minatojima-Minamimachi, Chuo, Kobe 650-0047, Japan.
Laboratory for in vitro Histogenesis, RIKEN Center for Developmental Biology, 2-2-3, Minatojima-Minamimachi, Chuo, Kobe 650-0047, Japan.
Development. 2016 Nov 1;143(21):3895-3906. doi: 10.1242/dev.134601. Epub 2016 Sep 15.
We previously demonstrated that mouse embryonic stem cell (mESC)-derived retinal epithelium self-forms an optic cup-like structure. In the developing retina, the dorsal and ventral sides differ in terms of local gene expression and morphological features. This aspect has not yet been shown in vitro Here, we demonstrate that mESC-derived retinal tissue spontaneously acquires polarity reminiscent of the dorsal-ventral (D-V) patterning of the embryonic retina. Tbx5 and Vax2 were expressed in a mutually exclusive manner, as seen in vivo Three-dimensional morphometric analysis showed that the in vitro-formed optic cup often contains cleft structures resembling the embryonic optic fissure. To elucidate the mechanisms underlying the spontaneous D-V polarization of mESC-derived retina, we examined the effects of patterning factors, and found that endogenous BMP signaling plays a predominant role in the dorsal specification. Further analysis revealed that canonical Wnt signaling, which was spontaneously activated at the proximal region, acts upstream of BMP signaling for dorsal specification. These observations suggest that D-V polarity could be established within the self-formed retinal neuroepithelium by intrinsic mechanisms involving the spatiotemporal regulation of canonical Wnt and BMP signals.
我们先前证明，小鼠胚胎干细胞（mESC）来源的视网膜上皮可自行形成视杯样结构。在发育中的视网膜中，背侧和腹侧在局部基因表达和形态特征方面存在差异。这一方面尚未在体外得到证实。在此，我们证明mESC来源的视网膜组织会自发获得极性，类似于胚胎视网膜的背腹（D-V）模式。Tbx5和Vax2以相互排斥的方式表达，这与在体内观察到的情况一致。三维形态计量分析表明，体外形成的视杯通常包含类似于胚胎视裂的裂隙结构。为了阐明mESC来源的视网膜自发D-V极化的潜在机制，我们研究了模式因子的作用，发现内源性BMP信号在背侧特化中起主要作用。进一步分析表明，在近端区域自发激活的经典Wnt信号在背侧特化中作用于BMP信号的上游。这些观察结果表明，D-V极性可以通过涉及经典Wnt和BMP信号时空调节的内在机制在自行形成的视网膜神经上皮内建立。
