LSD1辅抑制子Rcor2在小鼠胚胎新皮层发生过程中神经干细胞命运决定的作用及机制研究

Neocortical development is an elaborate process requiring exquisite regulation of the diverse processes including neurogenesis, neural migration and neural differentiation. Molecular mechanism underlying spatial specification of neural stem cells (NSCs) lineage is the research hot spot in neocortical development. Present studies mainly focus on the transcription factors, the microenvironment and signaling pathways, and specific epigenetic modifications. Previous studies showed that epigenetic factor Rcor1 (coREST) plays important roles in neocortical development by facilitating LSD1's demethylase activity on nucleosome. However, the function of Rcor2, which belongs to the same RCOR protein family and shares sequence similarity with Rcor1, is still unknown. Using multiple Rcor2-deficient or knock-in mouse models, this project is to study the function and mechanism of the LSD1 co-repressor, Rcor2 in NSCs fate determination and the progeny cell lineage specification during neocortical development by in vivo development tracing technique and in vitro differentiation system. Moreover, using high throughput sequencing and bioinformatics analysis, we try to illustrate the mechanism interaction between Rcor2 and Shh signaling pathway in NSCs fate specification in the developing neocortex. In summary, our study can deepen the understanding of epigenetic regulation and signaling pathways in neocortical NSCs fate determination and the progeny cell lineage specification during development. Based on the network between the two regulatory systems mentioned above, our study can further provide theoretical basis for the research and application of NSC in vitro differentiation system.

新皮层的发生是胚胎发育期神经发生、迁移和分化各个过程精妙调控的结果。新皮层中神经干细胞分化和子代细胞命运决定的分子机制更是研究的热点。之前的研究表明，表观遗传因子Rcor1（coREST）通过促进LSD1在核小体上的去甲基化活性，在新皮层发生中发挥作用。而同蛋白家族的Rcor2，其功能仍不清楚。 本项目以多种Rcor2缺陷或敲入的小鼠模型为研究对象，运用体内发育追踪和体外培养分化等技术，研究LSD1辅因子Rcor2在新皮层神经干细胞分化和子代细胞命运决定过程中的作用及机制；并结合高通量测序和生物信息学分析，探索Rcor2与Shh信号通路在神经干细胞的命运特化中的相互作用机制。 本项目的研究将在表观遗传调控系统与信号通路调控系统水平上深化对新皮层发生过程中神经干细胞命运决定机制的理解，并通过上述两种调控系统的之间的网络关系，为神经干细胞体外定向分化的优化提供理论依据。

新皮层发生过程中神经干细胞的分化和子代细胞命运决定的分子机制是神经生物学研究的热点。本项目以表观遗传因子Rcor2入手，通过研究Rcor2-LSD1组蛋白去甲基化酶复合物在新皮层发生过程中的重要作用及分子机制，深入解析了神经干细胞微环境中表观遗传调控与SHH信号通路调控之间的网络关系。在这些分子机制研究基础上，利用衰老小鼠为模型，系统比较了重编程-定向分化体系和直接转分化体系之间获得的神经元之间的差异及在临床应用上的偏好性，并建立了以生长因子和小分子化合物为基础的体细胞转分化手段，建立了神经祖细胞的新型培养体系。此外，我们成功建立了原态的人诱导多能干细胞系统，并继续利用上述技术体系深入研究新皮层发生过程中神经干细胞命运决定机制。