Tooth pulp as a source for neuronal precursor cells to study neurogenetic disorde

描述(申请人提供)：对Angelman、Rett和脆性X综合征等神经遗传性疾病以及自闭症谱系障碍的研究在很大程度上依赖于对淋巴母细胞和成纤维细胞等非神经性生物干细胞的基因/蛋白质表达的分析。虽然已经有可能对死后的人脑组织进行一些神经遗传综合征的分析，但这些组织的质量往往不同，而且数量有限。 最近，有一项从患者成纤维细胞中诱导多能干细胞(IPSCs)并将其分化为各种神经细胞的倡议。这种方法有几个问题：1)必须通过相当有侵入性的皮肤活检获得成纤维细胞，这会在发育障碍或自闭症儿童中留下疤痕并造成过度的疼痛和困扰；3)诱导成纤维细胞进入干细胞(重新编程)，然后进入神经元谱系是一项繁重的任务，可能无法在DNA上维持对本地神经组织的适当基因调控必不可少的表观遗传标记；4)本身具有免疫性的病毒载体被用来重新编程iPSC，以限制这些神经元的下游应用进行治疗性移植。在这里，我们建议使用脱落乳牙的牙髓(EPT)作为干细胞的来源，用于研究各种神经遗传综合征。牙髓干细胞在体外和体内均可分化为功能神经元。EPT牙髓也是一种容易获得的脑神经脊细胞来源。周围神经系统中的大多数细胞，包括神经元，都是从神经脊衍生出来的。基于我们在遗传学、牙髓干细胞和神经生理学方面的广泛合作经验，我们认为这一新方法将为我们在人类神经遗传疾病的体外模型系统中研究表达变化、表观遗传学和神经生理学提供一个新的视角。好了！ 公共卫生相关性：这项提案的主要目标是开发一种方法来研究使用脱牙(乳牙或牙髓)的神经遗传病患者的神经元。如果我们能确定牙齿样本在牙髓中提供了合适类型的细胞来培养神经元，我们就有了一种新的方法来看待这些患者来源的神经元的基因表达和生理。拥有这些培养物可以为人类神经遗传性疾病的机制，甚至是正常的神经元发育和功能带来新的见解。

DESCRIPTION (provided by applicant): The study of neurogenetic disorders like Angelman, Rett and fragile X syndromes as well as autism spectrum disorders has depended largely on the analysis of gene/protein expression in non-neuronal biospecimens like lymphoblast and fibroblast cell lines. Although some analysis has been possible in post-mortem human brain tissue for neurogenetic syndromes, this tissue is often of variable quality and in limited amounts. Recently there has been an initiative to induce pluripotent stem cells (iPSCs) from patient fibroblasts and differentiate these iPSCs into various neuronal lineages. There are several problems with this approach: 1) fibroblasts must be obtained though a fairly invasive skin biopsy which leaves a scar and causes undue pain and distress in developmentally disabled or autistic children; 3) induction of fibroblasts into stem cells (reprogramming) and then into neuronal lineages is a laborious task that may not maintain epigenetic marks on the DNA that are essential to proper gene regulation in the native neuronal tissues; and 4) viral vectors which are themselves immunogenic are used to reprogram iPSCs limiting the downstream aplication of these neurons for therapeutic transplantations. Here we propose to use dental pulps from exfoliated primary teeth (EPT), as a source of stem cells for the study of a variety of neurogenetic syndromes. Dental pulp stem cells differentiate into functional neurons in vitro and in vivo. Dental pulps from EPT are also an easily obtainable source of cranial neural crest (CNC) cells. The majority of the cells in the peripheral nervous system, including neurons, are derived from the neural crest. Based on the extensive collaborative sum of our expertise in genetics, dental pulp stem cells and neurophysiology, we feel that this novel approach will provide a fresh perspective to the way we study expresion changes, epigenetics and neurophysiology in an ex-vivo model system for human neurogenetic disorders. ! PUBLIC HEALTH RELEVANCE: The primary goal of this proposal is to develop a method to investigate the neurons of patients with neurogenetic disease that uses shed teeth (primary teeth or puled teeth). If we can determine that tooth samples provide the right type of cells in th dental pulp to make neurons in culture we will have a new way to look at the gene expression and physiology of these patient-derived neurons. Having these cultures could lead to new insights into the mechanisms of human neurogenetic disease and even normal neuronal development and function.