Epigenetic strategies for the in vitro generation of replacement beta cells

描述（由申请人提供）：本提案的总体目标是开发从人胚胎干细胞（hES）细胞或患者来源的诱导多能干细胞（iPS）细胞中获得葡萄糖反应性胰岛素生成细胞的策略。有了这个目标，我们的提案将推进NIH-NIDDK β细胞生物学联盟的重点领域之一，即“利用胰腺发育的线索直接从干细胞/祖细胞中分化细胞，用于糖尿病的细胞替代疗法”。为了实现我们的目标，我们已经组建了一个由五名研究人员组成的联盟，其中包括细胞和干细胞生物学以及基因组学方面的专家。通过对各种初级胚胎和成人细胞和组织中关键组蛋白修饰的全基因组定位，我们将定义定义胰腺祖细胞及其内分泌后代的表观遗传特征。这一知识将用于指导改善体外hES细胞分化为胰腺祖细胞和最终产生葡萄糖反应胰岛素的p细胞的工作。我们提出的关键是一种新的细胞微阵列技术，该技术允许组合筛选细胞外基质成分、因子和/或分子途径，以支持从hES细胞到成熟细胞的逐步分化路径中每个中间前体的有效生成。表观遗传特征将被用作评估体外生成的he细胞衍生细胞与体内胰腺细胞相似程度的终点。在移植到糖尿病小鼠模型后，最终将测试he细胞衍生的细胞纠正血糖水平升高的能力。

DESCRIPTION (provided by applicant): The overall objective of this proposal is to develop strategies for deriving glucose-responsive insulin-producing (-cells from human embryonic stem (hES) cells or patient-derived induced pluripotent stem (iPS) cells. With this objective our proposal will advance one of the focus areas of the NIH-NIDDK Beta Cell Biology Consortium, which is "to use cues from pancreatic development to directly differentiate (-cells from stem/progenitor cells for use in cell-replacement therapies for diabetes". To achieve our objectives we have assembled a consortium of five investigators, which includes experts in (-cell and stem cell biology as well as genomics. By genome-wide mapping of key histone modifications in a variety of primary embryonic and adult human cells and tissues, we will define epigenetic signatures that define pancreatic progenitors and their endocrine descendants. This knowledge will be used to guide efforts for improving preexisting in vitro differentiation protocols of hES cells into pancreatic progenitors and eventually glucose-responsive insulin-producing p-cells. Key to our proposal is a novel cellular microarray technology that allows for combinatorial screening of extracellular matrix components, factors and/or molecular pathways for their ability to support efficient generation of each intermediary precursor along the step-wise differentiation path from hES cell to mature (-cell. The epigenetic signatures will be used as endpoints to assess how closely the in vitro-generated, hES cell-derived cells resemble their in vivo pancreatic counterparts. hES cell-derived (-cells will eventually be tested for their ability to correct elevated blood glucose levels upon transplantation into diabetic mouse models. PUBLIC HEALTH RELEVANCE: Since the first pioneering work on islet transplantation, it has become clear that a cell-based approach for the treatment of diabetes mellitus can have significant benefits in terms of insulin independence and a reduced risk of hypoglycemia. By exploring novel startegies for deriving insulin-producing beta-cells from human embryonic stem cells for cell transplantation, this proposal seeks to develop cell therapies for diabetes.