Mechanistic studies of a PPAR-g mutation that causes lipodystrophy & diabetes

导致脂肪营养不良的 PPAR-g 突变的机制研究

• 批准号: 8531227
• 负责人: Olga Igor Astapova
• 金额: $ 4.31万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-08 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8531227
• 关键词: 2,4-thiazolidinedione; Adipose tissue; Adult; Affect; Binding; Binding Sites; Biological Assay; Cell Line; Cells; Complement; Complex; Consensus; DNA Binding; DNA Binding Domain; DNA Sequence; Data; Development; Diabetes Mellitus; Diabetes prevention; Disease; Doctor of Philosophy; Dyslipidemias; Electrophoretic Mobility Shift Assay; Energy Metabolism; Etiology; Event; Familial partial lipodystrophy; Family; Fibroblasts; Functional disorder; Gene Expression; Gene Expression Microarray Analysis; Gene Expression Profile; Gene Expression Regulation; Gene Targeting; Generations; Genes; Genetic Transcription; Goals; Human; Human Cell Line; Hypertension; Immunoblotting; In Vitro; Inflammation; Inherited; Insulin; Insulin Resistance; Insulin Signaling Pathway; Intracellular Accumulation of Lipids; Knowledge; Ligands; Light; Lipodystrophy; Luciferases; Mediating; Metabolic; Metabolic Diseases; Metabolic syndrome; Microarray Analysis; Molecular; Molecular Biology; Molecular Profiling; Mutation; Non-Insulin-Dependent Diabetes Mellitus; Nuclear Receptors; Obesity; PPAR gamma; Pathogenesis; Pathway interactions; Pattern; Peroxisome Proliferator-Activated Receptors; Pharmaceutical Preparations; Phenotype; Physiological; Play; Polycystic Ovary Syndrome; Population; Prevalence; Prevention; Production; Property; Recruitment Activity; Regulation; Reporter; Reporting; Response Elements; Reverse Transcriptase Polymerase Chain Reaction; Role; Specificity; Structure; Techniques; Thiazolidinediones; Transcriptional Activation; United States National Institutes of Health; base; chromatin immunoprecipitation; combat; improved; in vivo; insight; insulin sensitivity; insulin sensitizing drugs; loss of function mutation; mitochondrial dysfunction; mutant; promoter; receptor; research study; response; screening

DESCRIPTION (provided by applicant): Although insulin resistance is a key component of type II diabetes, the molecular mechanisms controlling insulin sensitivity have not been fully elucidated. Understanding the etiology of insulin resistance will therefore be of tremendous importance for developing better screening, treatment and prevention targets to combat the rising threat of metabolic disorders. Peroxisome proliferator-activated receptor gamma (PPARg) has been implicated in the insulin signaling pathway as the target of thiazolidinediones, drugs that have recently been employed in the management of insulin-resistant disorders for their insulin-sensitizing effects. PPARg is a ligand-activated nuclear receptor with a well-characterized structure that binds PPAR response elements and regulates transcription of target genes by recruiting coactivators and/or corepressors. Although many PPARg-regulated genes have been identified, the exact set of PPARg target genes that mediate improvements in insulin sensitivity in vivo is largely unknown. The goal of this project is to shed light on this issue by studying a unique, recently discovered PPARg mutation that causes familial partial lipodystrophy (FPLD), an extreme form of type II diabetes. This project will take advantage of the particular properties of this mutation, which makes a conservative single change (E157D) in the DNA binding domain of the receptor. Our preliminary data show that this mutation alters the DNA sequence recognition specificity of the receptor, resulting in a distinctly different pattern of transcription of several known PPARg target genes. These findings led to the hypothesis that forms the basis for this proposal: the E157D PPARg causes diabetes through misregulation of key metabolic genes. There are two specific aims: 1) Characterize the effects of the E157D mutation on DNA binding and transcriptional activation of a set of known PPARg target genes, and 2) Identify the global set of genes that are misregulated by E157D PPARg. Standard in vitro techniques for DNA binding and transcriptional activity will be used to compare mutant and wild type PPARg function. Human cell lines expressing wild-type and mutant PPARg will be generated, and microarray analysis of gene expression as well as chromatin immunoprecipitation analysis of selected genes will be used to identify genes misregulated by E157D PPARg. RELEVANCE. Results from this study will identify genes or sets of genes that were not previously recognized as being involved in the etiology of metabolic diseases such as lipodystrophy and in particular diabetes. This knowledge may advance possibilities for screening, treatment and prevention of diabetes and other metabolic diseases.

描述（由申请人提供）： 尽管胰岛素抵抗是II型糖尿病的关键组成部分，但控制胰岛素敏感性的分子机制尚未完全阐明。因此，了解胰岛素抵抗的病因对于开发更好的筛查，治疗和预防目标以应对代谢疾病的不断增长的威胁将非常重要。过氧化物酶体增殖物激活的受体伽马（PPARG）已与胰岛素信号通路有关，作为噻唑烷二酮的靶标，最近已在胰岛素敏感性效应的胰岛素抗性疾病管理中使用的药物。 PPARG是一种配体激活的核受体，具有良好的特征结构，结合PPAR响应元件并通过募集共激活因子和/或核心压力器来调节靶基因的转录。尽管已经鉴定出许多PPARG调节的基因，但介导体内胰岛素敏感性改善的PPARG靶基因的确切基因基本上是未知的。该项目的目的是通过研究一种独特的，最近发现的PPARG突变来阐明这个问题，该突变导致家族性部分脂肪营养不良（FPLD），这是II型糖尿病的极端形式。该项目将利用该突变的特定特性，这使得在受体的DNA结合结构域中导致保守的单个变化（E157D）。我们的初步数据表明，该突变改变了受体的DNA序列识别特异性，从而导致几种已知PPARG靶基因的转录模式截然不同。这些发现导致了构成该提议基础的假设：E157D PPARG通过关键代谢基因的不正调引起糖尿病。有两个具体的目的：1）表征E157D突变对一组已知PPARG靶基因的DNA结合和转录激活的影响，以及2）确定由E157D PPARG误导的全局基因集。 DNA结合和转录活性的标准体外技术将用于比较突变体和野生型PPARG功能。将产生表达野生型和突变体PPARG的人类细胞系，并将使用对所选基因的染色质免疫沉淀分析进行微阵列分析，以识别由E157D PPARG误导的基因。 关联。这项研究的结果将确定以前不是以前的基因或一组基因 被认为参与了代谢疾病（例如脂肪营养不良，尤其是糖尿病）的病因。这些知识可能会促进筛查，治疗和预防糖尿病和其他代谢疾病的可能性。