Regulation of beta cell identity and dedifferentiation

β细胞身份和去分化的调节

基本信息

批准号：
9268754
负责人：
Matthias Hebrok
金额：
$ 39.95万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-05-01 至 2019-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9268754
关键词：
Address Affect Animals Back Beta Cell Cell Differentiation process Cell physiology Cells Complex Data Defect Development Diabetes Mellitus Disease Exposure to Flowcharts Functional disorder Gene Activation Gene Expression Gene Targeting Genes Genetic Glucose Glucose Intolerance Glycolysis Goals Gray unit of radiation dose Health Human Individual Insulin Insulin Resistance Islet Cell Lead Maintenance Metabolic Metabolic stress Metabolism Modeling Molecular Non-Insulin-Dependent Diabetes Mellitus Obesity Oranges Outcome Oxidative Phosphorylation Pathway interactions Patients Peripheral Phenotype Play Population Protocols documentation Regulation Reporting Risk Factors Rodent Model Role Sampling Signal Pathway Structure of beta Cell of islet Testing Therapeutic Transgenic Animals Transgenic Mice Transgenic Organisms Translating VHL gene base blood glucose regulation cell dedifferentiation combinatorial comparative design diabetic diabetic patient experimental study genetic manipulation genetic regulatory protein genome wide association study human embryonic stem cell human stem cells islet mouse model mutant negative affect novel novel therapeutics overexpression pandemic disease prevent public health relevance stressor tool transcription factor

项目摘要

DESCRIPTION (provided by applicant): Type II Diabetes (T2D) is a debilitating disease that afflicts an ever-growing population throughout the world. In addition to obesity and insulin resistance contributing towards the development of the disease, beta cell dysfunction is increasingly implicated in promoting T2D. The reduction or loss of beta cell function due to a shift in the cellular state has reemerged as a contributor to disease. The mature state of the beta cell can be perturbed due to exposure to distinct stressors, and this results in loss of cellular identity or "de-differentiation". Numerous studies in rodent models have recently reported the occurrence of beta cell de-differentiation that then leads to diabetes. Significantly, T2D patient samples also have been reported to have a perturbation in the expression of key factors that are required for the maintenance of a fully functional beta cell. Identifying mechanisms that perturb the beta cell state that then contributes to the loss of glucose homeostasis is the overarching goal of this proposal. Complex mouse models that regulate gene expression in beta cells provide preliminary evidence of a modified beta cell "identity", i.e. a loss of canonical beta cell genes and activation of genes normally absent from a fully functional beta cell. In two mouse models (depletion of the von Hippel Lindau (VHL) gene and activation of the Sox9 transcription factor), erroneous activation of signaling pathways leads to beta cell de-differentiation and diabetes. Probing these transgenic tools allows for further exploration of the components downstream of these regulatory proteins that impact beta cell fate and function. The experiments outlined in this proposal focus on characterizing changes that occur in the pancreatic beta cells in both these mouse models, and validating the results in beta cells that we can now successfully generate from human embryonic stem cells (hESCs) using directed differentiation protocols. We have already conducted preliminary experiments and obtained data to support the hypothesis that novel factors dysregulated in ß-cells of the mutant animals can perturb beta cell identity and consequently function when expressed erroneously. In addition, we have generated a third model in which we observe ß-cell dysfunction caused by changes in the metabolic state of the cell, independent of de-differentiation defects. Thus, we have models in place to dissect different modulators of ß-cell dysfunction. State of the art combinatorial approaches combining the use of transgenic animals, hESC derived ß-cells, and human islets and ß-cells, will be employed to characterize the function of these factors in ß-cell dedifferentiation, metabolic defects, and dysfunction. Candidate factors will be tested for erroneous expression in samples isolated from T2D patients provided by nPOD. The overarching goal of these studies is to identify novel disruptors of ß-cell function whose activity could be modulated with the intent of preventing or reversing the compromised beta cell state back to a fully functional one in human patients.

描述（由适用提供）：II型糖尿病（T2D）是一种使人衰弱的疾病，遭受了全世界不断增长的人群的疾病。除了有助于疾病发展的肥胖和胰岛素抵抗外，β细胞功能障碍越来越涉及促进T2D。由于细胞状态变化而导致的β细胞功能的降低或损失已重新出现为疾病的贡献。由于暴露于不同的压力源，β细胞的成熟状态可能会受到干扰，这导致细胞身份丧失或“脱不同”。啮齿动物模型中的大量研究最近报道了β细胞脱不同的发生，然后导致糖尿病。显著地， T2D患者样品还据报道在维持功能良好的β细胞所需的关键因素的表达中具有扰动。确定贝塔细胞状态的机制，从而导致葡萄糖稳态的丧失是该提议的总体目标。调节基因表达在β细胞中的复杂小鼠模型提供了修饰的β细胞“身份”的初步证据，即通常没有功能性β细胞中通常不存在的基因的损失和基因的激活。在两个小鼠模型（Von Hippel lindau（VHL）基因的耗竭和SOX9转录因子的激活）中，信号通路的错误激活导致β细胞脱离二分化和糖尿病。探测这些转基因工具，可以进一步探索影响β细胞命运和功能的这些调节蛋白下游的成分。该提案中概述的实验集中于表征这两种小鼠模型中胰腺β细胞中发生的变化，并验证β细胞中的结果，我们现在可以使用有导分化方案从人类胚胎干细胞（HESC）成功地从人类胚胎干细胞（HESC）中产生。我们已经进行了初步实验，并获得了数据，以支持以下假设：突变动物的ß细胞失调的新因素可以扰动β细胞的身份，因此在错误地表达时起作用。此外，我们生成了第三个模型，在该模型中，我们观察到由细胞代谢状态变化引起的ß细胞功能障碍，而与脱节缺陷无关。因此，我们有适当的模型来剖定ß细胞功能障碍的不同调节剂。结合了转基因动物，hESC衍生的β细胞以及人类和ß细胞的使用状态，将采用使用这些因素在β-细胞去分化，代谢缺陷和功能障碍中的功能来表征这些因素的功能。候选因素将在NPOD提供的T2D患者中分离出的样品中测试错误的表达。这些研究的总体目标是确定β细胞功能的新型破坏者，其活性可以通过防止或逆转受损的β细胞状态回到人类患者中功能齐全的β细胞状态。