Genetic control of pancreatic endocrine cell development

描述（由申请人提供）：该项目将采用基于团队的方法进行三个直接相关的研究领域，这对于学习从其他细胞类型中制造新的胰腺β细胞很重要。在目标1中，我们寻求对胰腺发育过程中决定多种内分泌细胞类型形成的分子事件有更深入的了解。这将通过分离一系列高度纯化的祖细胞群体，进行数字基因表达分析，并制定生物信息学策略来表征离散细胞群体之间的差异，这将是暂时或遗传信息。在目标2中，我们将寻求利用在目标1中获得的知识来确定用于指导hESCs向胰腺细胞命运分化的方案的准确性，并通过监测在小鼠发育过程中特异性激活或抑制的基因簇的表达来合理改进这些方案。在Aim 3中，我们将开发新的小鼠系，其中三种转录因子的表达已被报道能够将胰腺腺泡转分化为β细胞，可以通过给予多西环素轻松调节。这些小鼠将用于探索转分化实际上是如何发生的，并确定新生成的β细胞的功能程度，并展示与真实β细胞相似的基因表达谱。本项目基于这样一个前提/假设：通常在小鼠发育过程中建立的多个基因调控网络必须在其他细胞类型的定向或反分化过程中建立，以实现临床使用所需的β细胞样功能。更多地了解胰腺特异性基因调控网络，它们如何在相关细胞群体中建立和差异，并确定它们在实验衍生的细胞群体中是否存在，将作为新发现和方案改进的平台。这个项目的六名研究人员有富有成效的合作互动的记录，并带来实现这些目标所必需的特定知识和能力。因此，预计该项目将产生重要的资源，不仅将推进β细胞生物学联盟的两个首要目标，而且还将具有广泛的科学影响和效用。

DESCRIPTION (provided by applicant): This project will use a team-based approach to pursue three directly interrelated areas of investigation important for learning to make new pancreatic beta cells from other cell types. In Aim 1 we seek to gain a deeper understanding of the molecular events that dictate formation of multiple endocrine cell types during pancreas development. This will be achieved by isolating a series of highly purified progenitor cell populations, performing digital gene expression analysis, and developing bioinformatics strategies for characterizing the differences among discrete cellular populations that will be temporally or genetically informative. In Aim 2 we will seek to utilize the knowledge gained in Aim 1 to determine the veracity of protocols being used to direct the differentiation of hESCs towards pancreatic cell fates and to rationally improve these protocols by monitoring the expression of gene clusters that are specifically activated or repressed during mouse development. In Aim 3 we will develop new mouse lines in which the expression of three transcription factors that have been reported to be capable of transdifferentiating pancreatic acinar to beta cells can be easily modulated by the administration of doxycycline. These mice will be used to explore how transdifferentiation actually occurs and to determine the extent to which the newly generated beta cells are functional and exhibit a gene expression profile similar to authentic beta cells. This project is based on the premise/hypothesis that multiple gene regulatory networks, which are normally set up during mouse development, must be established during directed or trans-differentiation of other cell types to achieve the beta cell-like functionalities necessary for clinical use. Greater knowledge of pancreas-specific gene regulatory networks, how they are established and differ among related cell populations, and determining whether they are present or absent in experimentally-derived cellular populations, will serve as a platform both for new discovery and protocol improvements. The six investigators in this project have a track record of productive collaborative interactions and bring specific knowledge and abilities necessary to accomplish these goals. Thus, it is anticipated that this project will generate important resources that will not only advance two of the overarching goals of the Beta Cell Biology Consortium but also have broad scientific impact and utility. PUBLIC HEALTH RELEVANCE: Type 1 and Type 2 diabetes are diseases that cause significant morbidity and mortality and thus have an adverse economic impact. Both diseases are characterized by the destruction or dysfunction of insulin-secreting pancreatic beta cells. This application seeks to gain key information for developing new, cell-based replacement therapies that hold promise for achieving better glucose control than is currently possible.