Neurogenesis: Career Development Plan in the Genetic and Modeling of Microcephaly

描述（由申请人提供）：人类遗传学，动物模型和最近添加到人类神经发育疾病建模工具箱的诱导多能干细胞（iPSCs）的结合有可能极大地扩展我们对人类疾病机制的理解。迄今为止，了解人类神经发育障碍的一个主要挑战是缺乏受影响的组织。iPSC能够从患者iPSC中分化神经组织的全部补体，从神经祖细胞（NP）到成熟的皮质神经元，这为理解人类疾病的独特特征开辟了一条令人兴奋的新途径。在这项应用中，我建议将这项新技术用于模拟常染色体隐性原发性小头畸形（MCPH）的神经发生缺陷。MCPH是一种神经发育障碍，其特征是在子宫内头部生长大大减少，并伴有非进行性智力迟钝。MCPH是大脑皮质发育不全和其他结构正常的大脑普遍缩小的结果，这种表型被认为是由于发育早期NP增殖缺陷造成的。MCPH非常适合这种新的建模方法，因为NPs在iPSC分化方案中早期分化，并且可以在神经花环的背景下评估增殖。为了将iPSCs体外建模数据与体内脑发育联系起来，我建议结合使用患者iPSCs、转基因小鼠iPSCs和动物模型。为了测试iPSC模型传达独特机制信息的敏感性，我建议对MCPH的两个遗传原因进行建模，这两个遗传原因应该以不同的方式或不同的严重程度扰乱同一组细胞。为了根据上述技术更全面地了解神经发生在MCPH分子病理学中的作用，我建议建立核孔蛋白107 （NUP107）和异常梭状样小头畸形相关（ASPM）的模型。我最近发现核孔蛋白107 (NUP107)，一个以前与人类疾病无关的基因，是MCPH的致病基因。为了进行拟议的研究，我从Nup107患者和对照成纤维细胞和嵌合小鼠中生成了iPSCs，用于条件Nup107基因诱捕等位基因（NUP107GT）。我还发现了一种新的ASPM突变，这是MCPH中最常见的突变基因，iPSC模型将作为独立研究者进行研究。从这种MCPH建模方法中获得的机制理解水平将为新的治疗方法和对正常人类大脑发育的见解奠定基础。

DESCRIPTION (provided by applicant): The combination of human genetics, animal models and the recent addition of induced pluripotent stem cells (iPSCs) to the human neurodevelopmental disease modeling toolbox has the potential to greatly expand our understanding of human disease mechanisms. To date, a major challenge to understanding human neurodevelopmental disorders has been the lack of affected tissue. The capacity of iPSCs to differentiate the full complement of neural tissue, from neural progenitors (NP) to mature cortical neurons, from patient iPSC opens an exciting new avenue to understanding unique human features of disease. In this application, I propose to tailor this new technology to model defects in neurogenesis which underlie autosomal recessive primary microcephaly (MCPH). MCPH is a neurodevelopmental disorder characterized by a great reduction of head growth in utero and is accompanied by nonprogressive mental retardation. MCPH is the result of cerebral cortex hypoplasia and generalized diminution of an otherwise architecturally normal brain, a phenotype that is thought to result from defective NP proliferation early in development. MCPH is well suited for this new modeling approach as NPs differentiate early in iPSC differentiation protocols and proliferation can be evaluated within the context of neural rosettes. To correlate iPSCs in vitro modeling data to in vivo brain development, I propose to utilize a combination of patient iPSCs, transgenic mouse iPSCs and animal models. To test the sensitivity of iPSC modeling to convey unique mechanistic information, I propose to model two genetic causes for MCPH that should perturb the same set of cells in different ways or with varying severity. To gain a more comprehensive understanding of the role of in neurogenesis in the molecular pathology of MCPH according to the techniques described above I am proposing to model both Nucleoporin 107 (NUP107) and abnormal spindle-like microcephaly associated (ASPM). I recently identified Nucleoporin 107 (NUP107), a gene not previously linked to human disease, as a causative gene for MCPH. To pursue the proposed research, I have generated iPSCs from Nup107 patient and control fibroblasts and chimeric mice for a conditional NUP107 gene trap allele (NUP107GT). I have also identified a novel ASPM mutation, the gene most commonly mutated in MCPH, for which iPSC modeling will be pursued as an independent investigator. The level of mechanistic understanding that can be gained from this modeling approach for MCPH will lay the foundation that can lead to new therapies and insights into how the normal human brain develops. PUBLIC HEALTH RELEVANCE: Primary microcephaly is a neurodevelopmental disorder presumably due to altered neurogenesis and causing a great reduction in brain growth. I have identified a new causative gene, NUP107, and propose to study induced-pluripotent stem cells and knockout mice to model this human disease.