The role of Pcif1 in pancreas development

PCif1在胰腺发育中的作用

基本信息

批准号：
8113918
负责人：
Jeffrey Charles Raum
金额：
$ 5.57万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-07-01 至 2013-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8113918
关键词：
Acinar Cell Activities of Daily Living Adult Affect Alleles Amylases Animals Attenuated Beta Cell Binding Cell Count Cell Maturation Cell physiology Cells Cellular Morphology Chronic Clinical Complement Data Defect Development Diabetes Mellitus Embryo Embryonic Development Endocrine Exocrine pancreas Genes Hormones Hyperglycemia Immunotherapy Insulin Intervention Islet Cell Islets of Langerhans Transplantation Knock-out Mediating Messenger RNA Modeling Morbidity - disease rate Mus Mutation Pancreas Patients Pattern Proteins Recruitment Activity Role Time Transcript Ubiquitin alternative treatment blood glucose regulation cell type defined contribution diabetic patient gain of function islet loss of function mouse model overexpression pancreas development progenitor protein expression public health relevance recombinase transcription factor treatment strategy

项目摘要

DESCRIPTION (provided by applicant): Current therapies aimed at the treatment of diabetes primarily consist of administration of exogenous insulin to maintain euglycemia, which is not nearly as effective as endogenous beta cells in controlling glucose homeostasis. Therefore therapies aimed at replacing (via islet transplantation) or maintaining beta cell function (immunotherapies) are currently being explored as alternative treatment strategies. The transcription factor Pdx-1 has been implicated as being central in pancreatic formation and adult beta cell function. Mutations of Pdx-1 and/or decreased Pdx-1 protein levels have been associated with defective pancreatic development and diabetes. As a result a concerted effort has been made to fully understand Pdx-1 function and identify Pdx-1 binding partners. Recently, the MATH-BTB protein, Pcif1 (or SPOP) has been identified as a Pdx-1 interacting protein and subsequently shown to recruit Pdx-1 for ubiquitin-mediated degradation. Preliminary results demonstrate that decreasing Pcif1 levels (Pcif1+/gt) on a Pdx-1 heterozygous background increases Pdx1 protein expression and attenuates the pancreatic defects seen in Pdx1+/- mice. Further, Pcif1gt/gt animals display expanded ss cell mass at the expense of other endocrine lineages and delayed acinar cell maturation. These results indicate Pcif1 modulates multiple targets in the pancreas. Thus we hypothesize that Pcif1 regulates the levels of key pancreatic transcription factors during development thereby allowing for the proper formation and maturation of both the exocrine and endocrine compartments. Specific Aim 1: To determine the role of Pcif1 in islet cell allocation and maturation. We will define the expression pattern of Pcif1 during pancreatic development and then examine the effect of loss of Pcif1 function on endocrine development by using a Pcif1 gene trap mouse. Islet cell formation will be analyzed to determine the mechanisms by which Pcif1 is affecting endocrine development. To complement the knockout studies, an inducible over-expression Pcif1 mouse model will be used to determine the impact of excess Pcif1 at the same critical time points in endocrine cell formation. Specific Aim 2:. To examine Pcif1 action on exocrine cell development. We wish to determine if Pcif1 is crucial in acinar formation and maturation. These studies will require the use of our Pcif1 null and Cre inducible Pcif1 mouse lines to define the contribution of Pcif1 function in the exocrine pancreas. Specifically, we will assess the role in acinar cell formation by quantifying cell numbers and the levels of proteins crucial for formation and function, including Ptf1a and amylase. ) PUBLIC HEALTH RELEVANCE: The elucidation of the role of Pcif1 in pancreas formation combined with its role in the adult can be used to better understand windows of clinical intervention to maintain beta cell mass in diabetic patients.

描述（由申请人提供）：目前旨在治疗糖尿病的疗法主要包括施用外源性胰岛素以维持血糖正常，其在控制葡萄糖稳态方面远不如内源性β细胞有效。因此，目前正在探索旨在替代（通过胰岛移植）或维持β细胞功能（免疫疗法）的疗法作为替代治疗策略。转录因子 Pdx-1 被认为是胰腺形成和成人 β 细胞功能的核心。 Pdx-1 突变和/或 Pdx-1 蛋白水平降低与胰腺发育缺陷和糖尿病有关。因此，我们共同努力全面了解 Pdx-1 功能并确定 Pdx-1 结合伙伴。最近，MATH-BTB 蛋白 Pcif1（或 SPOP）已被鉴定为 Pdx-1 相互作用蛋白，随后显示可招募 Pdx-1 进行泛素介导的降解。初步结果表明，降低 Pdx-1 杂合背景上的 Pcif1 水平 (Pcif1+/gt) 会增加 Pdx1 蛋白表达并减轻 Pdx1+/- 小鼠中观察到的胰腺缺陷。此外，PCif1gt/gt 动物表现出扩大的 SS 细胞质量，但以牺牲其他内分泌谱系和延迟腺泡细胞成熟为代价。这些结果表明 Pcif1 调节胰腺中的多个靶点。因此，我们假设 PCif1 在发育过程中调节关键胰腺转录因子的水平，从而允许外分泌和内分泌室的正确形成和成熟。具体目标 1：确定 Pcif1 在胰岛细胞分配和成熟中的作用。我们将定义胰腺发育过程中 Pcif1 的表达模式，然后使用 Pcif1 基因捕获小鼠检查 Pcif1 功能丧失对内分泌发育的影响。将分析胰岛细胞的形成，以确定 PCif1 影响内分泌发育的机制。为了补充敲除研究，将使用诱导性过度表达 Pcif1 小鼠模型来确定过量 Pcif1 在内分泌细胞形成的同一关键时间点的影响。具体目标2：。检查 PCif1 对外分泌细胞发育的作用。我们希望确定 PCif1 在腺泡形成和成熟中是否至关重要。这些研究需要使用我们的 Pcif1 null 和 Cre 诱导型 Pcif1 小鼠品系来确定 Pcif1 功能在外分泌胰腺中的贡献。具体来说，我们将通过量化细胞数量以及对形成和功能至关重要的蛋白质（包括 Ptf1a 和淀粉酶）水平来评估在腺泡细胞形成中的作用。）公共健康相关性：阐明 Pcif1 在胰腺形成中的作用及其在成人中的作用可用于更好地了解临床干预的窗口，以维持糖尿病患者的 β 细胞质量。