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

项目总结/摘要 糖尿病是一种全球流行病，预计将变得更加严重。虽然有治疗 选择，如外源性胰岛素，最有希望的长期治疗方法之一是移植供体胰岛 糖尿病患者。虽然这种治疗可以使患者维持正常的血糖水平， 长期以来，用于移植的可存活供体胰岛的量极度缺乏。到 为了解决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 将hPSC转化为β样细胞，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。这一做法取得了一定的成功，但目前 分化方案缺乏制备纯β细胞群的能力， 和多激素细胞群。更完整的知识的转录网络和相关 需要胰腺β细胞分化和功能所需的辅助因子来补充电流 hPSC分化方案，并提供更好的糖尿病治疗方案所需的信息。一 这种辅因子是染色体结构域解旋酶DNA结合蛋白4（CHD 4）。CHD 4是一种运动蛋白， 核小体重塑和脱乙酰酶（NuRD）复合物，以及沿着组蛋白脱乙酰酶1和2（HDAC 1 和2），CHD 4产生浓缩的染色质状态，从而抑制基因。初步数据显示， CHD 4与胰腺β细胞中的必需转录因子相互作用。另外，我的初步数据显示 小鼠β细胞中CHD 4的缺失导致高血糖沿着葡萄糖耐受不良。这表明 CHD 4是β细胞功能中必需的转录辅因子。更好地理解角色 CHD 4在胰腺β细胞的发育和功能中的作用可以提供额外的信息， hPSC体外定向分化为β细胞。在这个建议中，使用体内和体外 通过实验，我将确定CHD 4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.