CHD4-MEDIATED TRANSCRIPTIONAL REGULATION OF PANCREATIC BETA CELL DEVELOPMENT AND FUNCTION

项目摘要/摘要 糖尿病是一种全球流行病，预计会变得更加严重。尽管有治疗方法 选择，如外源性胰岛素，最有希望的长期治疗之一是移植供体胰岛 变成糖尿病患者。虽然这种治疗方法可以使患者在 随着时间的延长，可供移植的供体胰岛数量极度缺乏。至 为了应对缺乏合适的供体胰岛的问题，研究人员已经开始分化人类多能干细胞 (HPSC)转化为类β细胞，通过分泌胰岛素对葡萄糖做出反应，希望创造无限的供应 可移植的胰腺β细胞。这种方法在一定程度上是成功的；然而，目前的 分化方案缺乏制造纯β细胞群体的能力，并且经常导致未成熟的β细胞 和多荷尔蒙细胞群。对转录网络和相关的更完整的知识 胰腺β细胞分化和功能所需的辅因子需要补充电流 HPSC分化方案，并提供更好的糖尿病治疗方案所需的信息。一 这种辅因子就是染色体结构域解旋酶DNA结合蛋白4(CHD4)。CHD4是一种 核小体重构和脱乙酰酶(NuRD)复合体以及组蛋白脱乙酰酶1和2(HDAC1 和2)，CHD4产生浓缩的染色质状态，从而抑制基因。初步数据显示， CHD4与胰腺β细胞中的必需转录因子相互作用。此外，我的初步数据显示 小鼠β细胞中CHD4的缺失会导致高血糖和葡萄糖耐量异常。这表明 提示CHD4是β细胞功能所必需的转录辅因子。更好地理解这一角色 CHD4在胰腺β细胞的发育和功能中发挥的作用可以提供更多的信息以便于 β细胞体外定向分化的研究。在这个方案中，使用体内和体外两种方法 实验中，我将确定CHD4在发育和功能中的作用和机制 胰腺β细胞。

PROJECT SUMMARY / ABSTRACT Diabetes is a global epidemic that is expected to become even more severe. Although there are treatment options, such as exogenous insulin, one of the most promising long-term treatments is transplanting donor islets into diabetic patients. While this treatment can allow patients to maintain normal blood glucose levels for extended periods of time, there is an extreme lack in the amount of viable donor islets for transplantation. To combat the lack of suitable donor islets, researchers have begun to differentiate human pluripotent stem cells (hPSCs) into β-like cells that respond to glucose by secreting insulin, with the hopes of creating a limitless supply of transplantable pancreatic β cells. This approach has been somewhat successful; however, the current differentiation protocols lack the ability to make pure populations of β cells and often result in immature β cells and polyhormonal cell populations. More complete knowledge of the transcriptional networks and associated cofactors required in the differentiation and function of pancreatic β cells is needed to supplement the current hPSC differentiation protocols and provide the information required for better diabetes treatment options. One such cofactor is the chromodomain helicase DNA-binding protein 4 (CHD4). CHD4 is the motor protein of the nucleosome remodeling and deacetylase (NuRD) complex and, along with histone deacetylase 1 and 2 (HDAC1 and 2), CHD4 creates condensed chromatin states, thereby repressing genes. Preliminary data has shown that CHD4 interacts with essential transcription factors in pancreatic β cells. Furthermore, my preliminary data shows that the loss of CHD4 in the β cells of mice causes hyperglycemia along with glucose intolerance. This suggests that CHD4 is a necessary transcriptional cofactor in the function of β cells. A better understanding of the role CHD4 plays in the development and function of pancreatic β cells could provide additional information to facilitate the directed differentiation of β cells from hPSCs in vitro. In this proposal, using both in vivo and in vitro experiments, I will determine the role and mechanism of CHD4 in the development and function of pancreatic β cells.