Regulation of exocrine pancreas formation

描述（由申请人提供）：胰腺是由内分泌、外分泌和导管上皮隔室组成的复合腺体，在代谢功能和消化活动的调节中发挥核心作用。与胰腺的这些隔室相关的功能障碍分别导致糖尿病、胰腺炎和胰腺癌。尽管它们的功能不同，但所有的胰腺细胞类型都来源于前肠内胚层的共同祖细胞群。近年来，我们对启动腹侧和背侧胰腺原基形成和分化的环境信号的理解取得了重大进展。此外，Pdx 1和Ptf 1a已被确定为两个关键的调节因子，合作，以确定这些原基内的胰腺多能祖细胞的命运规范。最近，Foxa 1和Foxa 2已被证明是必不可少的生长和分化的胰腺原基和Pdx 1的调节。除了这些因素，很少有人知道胰腺程序的启动前肠内胚层的分子调控。此外，虽然大量的转录因子是必不可少的胰岛规格，分化和发展的特点，很少有人知道的外分泌胰腺的规格和发展。在这里提出的研究中，我们将调查的作用，两个加塔因子家族成员，Gata 4和Gata 6，在调节胰腺原基规格和外分泌胰腺的发展和分化。我们使用Gata 4和Gata 6的条件性敲除等位基因的初步数据表明，它们在这些调控过程中具有部分冗余功能。此外，我们推测加塔蛋白可能与FoxA蛋白协同调控Pdx 1，而加塔4蛋白可能与Ptf 1a协同调控外分泌特异性基因转录。我们打算探索Gata 4和Gata 6在早期胰腺形成和外分泌分化中的各自作用，具体目标如下：在具体目标1中，我们将使用Sox 9+和Pdx 1+胰腺原基中的加塔基因的条件性基因切除，结合遗传谱系追踪来表征Gata介导的胰腺原基形成的调节。在具体目标2中，我们将研究加塔因子在外分泌细胞发育中的各自作用。在具体目标3中，我们将通过探索Gata 4和Ptf 1a或Gata 4和Foxa 2之间的遗传和物理相互作用，并确定它们各自在调节胰腺基因表达和发育中的协同活性，来研究Gata 4在胰腺特异性基因表达中的分子作用。我们还将使用全局ChIP-Seq和RNA-Seq分析来识别胰腺中受Gata 4和/或Gata 6调控的基因组。 公共卫生相关性：胰腺是一个由内分泌、外分泌和导管上皮组成的复合腺体，在代谢功能和消化活动的调节中起核心作用。与胰腺的这些隔室相关的功能障碍分别导致糖尿病、胰腺炎和胰腺癌。本文提出的研究将确定和表征有助于胰腺，特别是外分泌胰腺的形成和功能的主要调控途径，以改善胰腺疾病的治疗和组织替代疗法。

DESCRIPTION (provided by applicant): The pancreas is a compound gland comprised of endocrine, exocrine and ductal epithelial compartments that play central roles in the regulation of metabolic functions and digestive activities. Dysfunctions associated with these compartments of the pancreas lead to diabetes, pancreatitis and pancreatic cancer, respectively. Despite their diverse functions, all of the pancreatic cell-types arise from a common progenitor population derived from the foregut endoderm. In recent years, significant advances have been made in our understanding of the environmental signals that initiate the formation and differentiation of the ventral and dorsal pancreatic primordia. Furthermore, Pdx1 and Ptf1a have been identified as two key regulatory factors that cooperate to determine the fate specification of the pancreatic multipotent progenitor cells within these primordia. More recently, Foxa1 and Foxa2 have been shown to be essential for the outgrowth and differentiation of the pancreatic primoridia and the regulation of Pdx1. Beyond these factors, little is known about the molecular regulation of the initiation of the pancreatic program from the foregut endoderm. In addition, although a large number of transcription factors that are essential for pancreatic islet specification, differentiation and development have been characterized, little is known about the specification and development of the exocrine pancreas. In the studies proposed here, we will investigate the roles of two Gata factor family members, Gata4 and Gata6, in the regulation of pancreatic primordia specification and in the development and differentiation of the exocrine pancreas. Our preliminary data using conditional knockout alleles of Gata4 and Gata6 suggest they have partially redundant functions in these regulatory processes. Furthermore, we propose that the Gata proteins may cooperate with the FoxA proteins in the regulation of Pdx1, and Gata4 may cooperate with Ptf1a in the regulation of exocrine- specific gene transcription. We intend to explore the respective roles of Gata4 and Gata6 in early pancreas formation and exocrine differentiation in the following specific aims: In Specific aim 1 we will characterize Gata-mediated regulation of pancreatic primordia formation using conditional gene ablation of the Gata genes in the Sox9+ and Pdx1+ pancreatic primordia, combined with genetic lineage tracing. In Specific aim 2 we will investigate the respective roles of the Gata factors in exocrine cell development. In Specific aim 3 we will investigate the molecular role of Gata4 in pancreas- specific gene expression by exploring genetic and physical interactions between Gata4 and Ptf1a or Gata4 and Foxa2 and determining their respective cooperative activities in regulating pancreas gene expression and development. We will also use global ChIP-Seq and RNA-Seq analysis to identify the set of genes regulated by Gata4 and/or Gata6 in the pancreas. PUBLIC HEALTH RELEVANCE: The pancreas is a compound gland comprised of endocrine, exocrine and ductal epithelial compartments that play central roles in the regulation of metabolic functions and digestive activities. Dysfunctions associated with these compartments of the pancreas lead to diabetes, pancreatitis and pancreatic cancer, respectively. The studies proposed here will identify and characterize the primary regulatory pathways that contribute to the formation and function of the pancreas, especially the exocrine pancreas, to improve treatment and tissue replacement therapies of pancreatic diseases.