Sox19b在神经管发育缺陷中的新作用及机制研究

Neural Tube Defects (NTDs) is the most serious and common disease of the birth defects. The proliferation, differentiation and migration of the neural stem cells (NSCs) is the cellular basis of neural tube development. The transcription factor SoxB1 has a curial role in controlling the proliferation and differentiation of the NSCs. A significant decreased or totally lost of SoxB1 expression was found in NTDs’ patients. Our preliminary data demonstrated that the inhibition of Sox19b induced many NTDs phenotypes (e.g. narrowed forebrain and curved tail), premature differentiation of NSCs in neurons, and remarkable reduced expression of epigenetic factors Ezh2. On the basis of above finding, we will determine the role Sox19b in NTDS and the mechanism(s) through which Sox19b contributes to NSCs by utilizing histologic section, in situ hybridization, qPCR, etc. We next use TEM and ChIP to dissect the role of Ezh2 in chromatin remodeling, histone modification in mediating NTDs outcomes. This study will determine the roles of Sox19 in NTDs and establish a network of gene regulation in NSCs in genetic and epigenetic levels, thereby shed light on the future strategies for therapeutic targeting.

神经管发育缺陷（NTDs）是最严重、最常见的出生缺陷疾病之一。神经干细胞（NSCs）的增殖、分化、迁移等过程是神经管发育的细胞学基础，SoxB1家族是调控NSCs增殖分化的重要转录因子，NTDs患者表现出SoxB1缺失或表达显著降低的现象。本课题前期研究发现抑制斑马鱼SoxB1家族成员Sox19b，胚胎表现出前脑减小甚至缺失，尾部向上弯曲等NTDs表型，并首次发现神经管中NSCs过早分化，重要表观遗传因子Ezh2的表达显著降低。本研究拟在前期研究基础上，通过组织切片、原位杂交、qPCR等技术，探讨Sox19b在NTDs中的作用和对NSCs的调控机制；利用透射电镜、ChIP等技术，研究染色质结构、组蛋白修饰的变化，阐明调控Ezh2的分子机制。本研究揭示了Sox19b在NTDs中的新作用，建立了转录因子与表观遗传因子对NSCs的调控网络，为NTDs的临床治疗提供新的线索和理论指导。

神经管发育是指从神经板出现到神经管关闭的连续的发育过程。神经管发育缺陷（NTDs）是最严重、最常见的出生缺陷疾病之一。而神经干细胞（NSCs）的增殖、分化、迁移等过程是神经管发育的细胞学基础。本课题利用斑马鱼模式动物借助Mo技术成功构建了斑马鱼神经管畸形在体模型，研究了神经发育重要转录因子SOX19b在神经管发育过程中的重要作用。Sox19b是含HMG-box结构域的转录因子，敲低Sox19b后斑马鱼胚胎前脑缺失或减小，尾部上翘，神经管发育异常，神经外胚层的标记蛋白表达减少，神经管内神经干细胞（NSCs）过早分化成为神经元，干性细胞数目降低，重要表观遗传因子Ezh2的表达显著降低，组蛋白H3K27me在分化相关基因启动子区的定位减少。本研究通过组织切片、原位杂交、qPCR等技术，探讨Sox19b在NTDs中的作用和对NSCs的调控机制；利用Western blot、ChIP等技术，研究组蛋白修饰的变化，阐明调控Ezh2的分子机制。本研究揭示了Sox19b在NTDs中的新作用，建立了转录因子与表观遗传因子对NSCs的调控网络，为NTDs的临床治疗提供新的线索和理论指导。