The Role of microRNA in Pancreas Development

描述（由申请人提供）：本提案的目标是确定小的非编码microRNA（miRNA）在胰岛发育中的作用。我们假设miRNA调节控制胰岛发育的基因的表达。尽管已知miRNA影响几种组织的发育，并且它们已经涉及成熟β细胞中葡萄糖刺激的胰岛素分泌，但先前尚未探索miRNA在胰腺发育中的作用。该提案的具体目标是建立miRNA在胰腺和胰岛发育中的全球作用，并了解单个miRNA的作用：1.通过去除Dicer或DGCR 8（加工miRNA途径的两种组分），检测miRNA在胰腺发育中的重要性，其中Dicer或DGCR 8来自具有pdx 1-cre的早期胰腺前体细胞、具有ngn 3-cre的早期胰岛前体细胞和具有ins 2-cre的成熟β细胞。2.确定胰腺发育过程中miRNA的表达模式。我们将使用我们已经开发和测试的miRNA寡核苷酸微阵列、原位杂交和BAG转基因技术来确定胰腺发育过程中miRNA的表达模式。3.检测特异性miRNA在调节胰腺转录因子表达中的作用。基于预测的miRNA靶点，我们将专注于同源域因子Nkx6.1的调控。4.建立胰腺中miRNA表达的调控机制。我们将专门测试胰腺转录因子Sox 9、Neurogenin 3和Nkx 2.2对miRNA的调控。这些研究将帮助我们了解胰岛细胞是如何分化的，以及miRNA在这一过程中的作用。更好地了解胰岛细胞如何分化将有助于开发为糖尿病患者生产胰岛细胞的方法。

DESCRIPTION (provided by applicant): The goal of this proposal is to determine the role of small non-coding microRNAs (miRNA) in pancreatic islet development. We hypothesize that miRNA regulate the expression of genes controlling islet development. Although miRNA are known to influence the development of several tissues, and they have been implicated in glucose-stimulated insulin secretion in mature beta-cells, the role of miRNA in pancreatic development has not been explored previously. The specific aims of this proposal are to establish the global role of miRNA in pancreas and islet development and to understand the role of individual miRNA: 1. Test the importance of miRNA in pancreas development by removing either Dicer or DGCR8, two components of the pathway for processing miRNA, from early pancreatic precursor cells with pdx1-cre, early islet precursor cells with ngn3-cre, and mature beta-cells with ins2-cre. 2. Determine the expression pattern of miRNAs during pancreas development. We will use miRNA oligonucleotide microarrays that we have already developed and tested, in situ hybridization, and BAG transgenics to determine the expression pattern of miRNAs during pancreatic development. 3. Test the role of specific miRNA in regulating expression of pancreatic transcription factors. Based on predicted miRNA targets, we will focus on the regulation of homeodomain factor Nkx6.1. 4. Establish the mechanisms for regulation of miRNA expression in the pancreas. We will test specifically for regulation of miRNA by pancreatic transcription factors Sox9, Neurogenin3 and Nkx2.2. These studies will help us understand how islet cells differentiate and the role of miRNA in that process. A better understanding of how islet cells differentiate will help in developing methods for producing islet cells for patients with diabetes.