Transcriptional Control of Dendritic Arbor Formation in the Mammalian Neocortex by Sip1

Sip1 对哺乳动物新皮质中树突状乔木形成的转录控制

• 批准号: 327985466
• 负责人: Professorin Dr. Marta de Rocha Rosário
• 金额: --
• 依托单位: Institut für Zell- und Neurobiologie (CCM)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/327985466?language=en
• 关键词: Transcriptional; Control; Dendritic; Arbor; Formation

The cerebral neocortex processes higher brain functions such as decision-making and cognitive thought. The principle neurons that make up the neocortex, the pyramidal cells, have elaborately branched, neuronal subtype-specific dendritic arbors that contain specialized sites for information acquisition, the dendritic spines. Indeed, defective formation and maturation of the dendritic arbor during development results in defective neuronal connectivity and is associated with cognitive impairment in a wide number of human neurodevelopmental disorders. Work by our group and others, has begun to identify the signaling cascades that direct initiation of branching and spine maturation, but much remains unclear. The transcriptional regulation of these processes in particular, is still poorly understood.Heterozygous mutations in the transcription factor Sip1 (also called ZFHX1b or ZEB2) have been shown to cause Mowat-Wilson syndrome, a human condition associated with severe intellectual disability, multiple congenital abnormalities and epilepsy. The cellular and molecular mechanisms that lead to impaired cognition in this condition are not known. Our preliminary data has revealed a novel critical role for Sip1 in the formation of the dendritic arbor during development of the mammalian neocortex. Moreover, our results point to a requirement for Sip1 in at least two distinct steps of dendritic arborisation: in the acquisition of polarity and in determining the extent of branching complexity. This project therefore aims to investigate the roles of Sip1 in the specification and formation of dendritic branches and spines and, furthermore, to identify the downstream signalling mechanisms that regulate these processes in the mammalian neocortex during development. We will generate mosaic deletion of Sip1 in the mammalian neocortex by in utero electroporation, and combine this with both live-imaging and immunofluorescent stainings to investigate the possible roles of Sip1 at each step of dendritic arborisation and maturation: from determination of the apical dendrite to the establishment of synaptic contact. Furthermore, the project will use Sip1 effector mutations, transcriptome Deep-Sequencing of FACS sorted Sip1-deficient neurons and available microarray data to identify the downstream targets involved. Identified targets will be functionally analysed in vivo using in utero electroporation. We intend thereby to further our understanding of the cellular and molecular regulation of neuronal network formation in the neocortex and provide insights to the development of cognitive impairment as occurs in Mowat-Wilson disease.

大脑新皮层处理更高级的大脑功能，如决策和认知思维。构成新皮层的主要神经元是锥体细胞，它们具有精心分支的、神经元亚型特异性的树突状乔木，其中包含用于信息获取的专门位点，即树突棘。事实上，发育过程中树突状乔木的形成和成熟缺陷导致神经元连接缺陷，并与许多人类神经发育障碍中的认知障碍相关。我们小组和其他人的工作已经开始确定直接启动分支和脊柱成熟的信号级联，但仍有很多不清楚。转录因子Sip 1（也称为ZFHX 1b或ZEB 2）的杂合突变已被证明会导致Mowat-Wilson综合征，这是一种与严重智力残疾、多种先天性异常和癫痫相关的人类疾病。在这种情况下导致认知受损的细胞和分子机制尚不清楚。我们的初步数据揭示了一种新的关键作用Sip 1在哺乳动物新皮层发育过程中的树突状乔木的形成。此外，我们的研究结果指出，在至少两个不同的步骤的树突状arborisation的Sip 1的要求：在收购的极性，并在确定分支的复杂程度。因此，该项目旨在研究Sip 1在树突状分支和棘的规范和形成中的作用，并进一步确定在发育过程中调节哺乳动物新皮层中这些过程的下游信号传导机制。我们将通过子宫内电穿孔在哺乳动物新皮层中产生Sip 1的嵌合缺失，并将其与实时成像和免疫荧光染色结合联合收割机，以研究Sip 1在树突分支和成熟的每个步骤中的可能作用：从确定顶端树突到建立突触接触。此外，该项目将使用Sip 1效应突变，FACS分选的Sip 1缺陷神经元的转录组深度测序和可用的微阵列数据来鉴定所涉及的下游靶点。将使用子宫内电穿孔在体内对鉴定的靶标进行功能分析。因此，我们打算进一步了解新皮层神经元网络形成的细胞和分子调控，并为Mowat-Wilson病中发生的认知障碍的发展提供见解。