ATF3 in Beta cell signaling, expression & destruction

ATF3 在 Beta 细胞信号传导、表达中的作用

• 批准号: 7017740
• 负责人: TSONWIN HAI
• 金额: $ 27.91万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2008-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7017740
• 关键词: biological signal transduction; cAMP response element binding protein; cell death; cell proliferation; cytokine; diabetes mellitus; diabetes mellitus genetics; gene induction /repression; genetically modified animals; glutathione; hyperglycemia; hyperlipidemia; immunocytochemistry; interleukin 1; laboratory mouse; mitogen activated protein kinase; nitroso compounds; nuclear factor kappa beta; pancreatic islets; pathologic process; streptozotocin

DESCRIPTION (provided by applicant): Goal and Significance: Diabetes is a major health problem in the U.S. Many years of research indicate that beta cell destruction plays an important role in the pathogenesis and complication of diabetes. The goal of this proposal is to elucidate the roles of Activating Transcription Factor 3 (ATF3), a stress-inducible gene, in stress-induced signal transduction, beta cell dysfunction and destruction. The proposed research will test the following hypotheses. (1) Aim 1: To test the hypothesis that ATF3 is induced in beta cells by stress signals, at least in part, through the MAPK and NFkB pathways. Dominant negative molecules that block the activation of these pathways will be used to determine whether they could inhibit the induction of ATF3 in beta cells by stress signals (IL-1beta, hyperglycemia, and hyperlipidemia). In addition, constitutively active mutants that activate these pathways will be used to determine whether they could induce the expression of ATF3 in the absence of exogenously applied signals. (2) Aim 2: To test the hypothesis that expression of ATF3 leads to beta cell dysfunction, destruction and the development of diabetes. The mifepristone-inducible system will be used to generate transgenic mice expressing ATF3 in the islets in an inducible manner. These mice will be characterized for morphological, immunohistochemical and physiological parameters, and for islet cell death and cell proliferation. (3) Aim 3: To test the hypothesis that ATF3 plays an essential role in cytokine-induced beta cell dysfunction and destruction. Islet cells will be isolated from wild type (ATF3+/+), heterozygous (ATF3+/-) and homozygous (ATF3-/-) ATF3 knockout mice. Cells will be subjected to pro-inflammatory cytokines, nitric oxide donor S-nitroso glutathione (GSNO), or medium (control). Cell death will be analyzed at various time points to determine whether ATF3 is "necessary" for stress signals to induce efficient beta cell death. In addition, islet functions will be analyzed to determine whether ATF3 is necessary for cytokines to induce beta cell dysfunction. For in vivo experiments, wild type and knockout mice will be injected with streptozotocin (STZ) to induce diabetes. Blood glucose levels and diabetes incidence will be analyzed to determine whether ATF3 knockout mice are less sensitive to STZ than wild type mice.

描述（由申请人提供）：目标和意义：糖尿病是美国的主要健康问题，多年来的研究表明，β细胞破坏在糖尿病的发病机理和并发症中起着重要作用。该提案的目的是阐明激活转录因子3（ATF3）（ATF3）（ATF3），一种可诱导的基因，在应力诱导的信号转导，β细胞功能障碍和破坏中的作用。拟议的研究将检验以下假设。 （1）目的1：测试以下假设：ATF3通过压力信号至少部分通过MAPK和NFKB途径诱导Beta细胞。阻止这些途径激活的主要负分子将用于确定它们是否可以通过应力信号（IL-1BETA，高血糖和高脂血症）抑制β细胞中ATF3的诱导。另外，激活这些途径的组成性活性突变体将用于确定在没有外源性信号的情况下是否可以诱导ATF3的表达。 （2）目标2：检验以下假设：ATF3的表达导致β细胞功能障碍，破坏和糖尿病的发展。米非酮诱导的系统将用于以诱导方式在胰岛中表达ATF3的转基因小鼠。这些小鼠的特征是形态学，免疫组织化学和生理参数，以及胰岛细​​胞死亡和细胞增殖。 （3）目的3：检验以下假设：ATF3在细胞因子诱导的β细胞功能障碍和破坏中起着至关重要的作用。胰岛细胞将从野生型（ATF3+/+），杂合（ATF3 +/-）和纯合子（ATF3 - / - ）ATF3敲除小鼠中分离出来。细胞将受到促炎性细胞因子，一氧化氮供体S-硝基谷胱甘肽（GSNO）或培养基（对照）的影响。将在各个时间点分析细胞死亡，以确定应力信号是否“必要”诱导有效的β细胞死亡。另外，将分析胰岛功能，以确定细胞因子诱导β细胞功能障碍是否必要。对于体内实验，将向野生型和基因敲除小鼠注射链蛋白酶（STZ）以诱导糖尿病。将分析血糖水平和糖尿病的发病率，以确定ATF3基因敲除小鼠对STZ的敏感性是否不如野生型小鼠敏感。