Epigenomic Profiling of Normal and Diabetic Pancreatic Beta-Cells

描述（由申请人提供）：糖尿病是一种终身慢性疾病，2007年全球患病率估计为1.8亿患者。在过去的十年中，已经清楚的是，胰腺细胞的衰竭是导致转变为显性糖尿病的最终事件，尽管肥胖和外周胰岛素抵抗是导致糖尿病前期的因素。在此，细胞衰竭被定义为两种功能的丧失，即葡萄糖刺激的胰岛素分泌，以及由于细胞凋亡增加或不能响应代谢需求而增殖而导致的细胞质量不足。虽然有几种药物用于减少胰岛素抵抗和增加胰岛素分泌，但没有一种药物能够解决 - 电池故障事实上，目前还没有一个好的靶点可以允许这种药物的开发。因为细胞在糖尿病的发病机制中起着如此重要的作用，并且由于表观遗传因素（即，反映在染色质状态中的转录程序的长期变化）可能是导致糖尿病的生活方式变化和环境因素的主要后果，我们将确定健康和2型糖尿病人类细胞的表观基因组。这项工作将为确定未来可以靶向的途径和基因奠定基础，以开发解决细胞衰竭的新疗法。具体来说，我们将使用ChIP-Seq技术确定从50名健康和50名2型糖尿病器官供体中分离的细胞中激活和抑制染色质标记。其次，我们将分析相同的细胞制剂中的microRNA谱，因为miRNAs是修饰糖尿病细胞转录组的强有力的候选者。第三，我们将分析在宾夕法尼亚大学发现的一种新的染色质标记，该标记将应激介质AMPK与染色质状态联系起来。第四，我们将进行全面的计算生物学分析，以确定糖尿病细胞中受影响的节点和调控途径。 公共卫生相关性：糖尿病是一种终身慢性疾病，2007年全球患病率估计为1.8亿患者。在过去的十年中，已经清楚的是，胰腺β细胞（胰岛素产生细胞）的衰竭是导致转变为显性糖尿病的最终事件，即使肥胖和外周胰岛素抵抗是导致糖尿病前期的因素。我们将确定“表观遗传”，即不是基于突变的，糖尿病β细胞基因组中导致其失败的变化。这项工作将确定治疗2型糖尿病的新的潜在药物靶点。

DESCRIPTION (provided by applicant): Diabetes mellitus is a lifelong chronic disease with worldwide prevalence estimated at 180 million patients in 2007. Over the past decade, it has become clear that failure of the pancreatic ¿-cell is the final event causing the transition to overt diabetes, even though obesity and peripheral insulin resistance are the factors leading to pre-diabetes. ¿-cell failure here is defined as loss of both function, i.e. glucose stimulated insulin secretion, and inadequate ¿-cell mass, either by increased apoptosis or a failure to proliferate in response to metabolic demand. While several drugs are in use to reduce insulin resistance and increase insulin secretion, none exist that address ¿-cell failure. In fact, at present, no good targets are known that would allow such drug development. Because the ¿-cell plays such a central role in the pathogenesis of diabetes, and because epigenetic factors (i.e. long term changes in the transcriptional program reflected in chromatin status) are likely to be the predominant consequence of the life-style changes and environmental factors that lead up to diabetes, we will determine the epigenome of both healthy and type 2 diabetic human ¿-cells. This effort will lay the groundwork to defining the pathways and genes that can be targeted in the future for the development of new therapies that address ¿-cell failure. Specifically, we will determine both activating and repressing chromatin marks in ¿-cells isolated from 50 healthy and 50 type 2 diabetic organ donors using ChIP-Seq technology. Secondly, we will analyze the microRNA profile in the same ¿-cell preparations, as miRNAs are strong candidates to modify the transcriptome of the diabetic ¿-cell. Third, we will analyze a novel chromatin mark discovered at Penn that links the stress mediator AMPK to chromatin status. Fourth, we will perform a comprehensive computational biology analysis to identify the nodes and regulatory pathways that are affected in diabetic ¿-cells. PUBLIC HEALTH RELEVANCE: Diabetes mellitus is a lifelong chronic disease with worldwide prevalence estimated at 180 million patients in 2007. Over the past decade, it has become clear that failure of the pancreatic beta-cell, the insulin producing cell, is the final event causing the transition to overt diabetes, even though obesity and peripheral insulin resistance are the factors leading to pre- diabetes. We will determine the "epigenetic", that is not mutation based, changes in the genome of the diabetic beta-cell that cause it to fail. This work will identify new potential drug targets for the treatment of type 2 diabetes.