Hepatic TNF Receptor Associated Factor (TRAF) 3 Promotes Insulin Resistance through the Ubiquitination of Insulin Receptor Substrate (IRS) 1 and 2

肝 TNF 受体相关因子 (TRAF) 3 通过胰岛素受体底物 (IRS) 1 和 2 的泛素化促进胰岛素抵抗

• 批准号: 9440666
• 负责人: Mark Jimenez-Canet
• 金额: $ 0.18万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9440666
• 关键词: Adaptor Signaling Protein; Adenoviruses; Affect; Affinity; American; Analytical Chemistry; Antibodies; Area; Biological Assay; Cardiovascular Diseases; Cause of Death; Cells; Chronic; Complex; Cytokine Signaling; Data; Development; Disease; Disease Progression; Epidemic; Etiology; Functional disorder; Future; Gene Expression Regulation; Genetic; Glucagon; Health; Hepatic; Hepatocyte; High Fat Diet; Hyperglycemia; IRS1 gene; IRS2 gene; In Vitro; Individual; Inflammation; Inflammation Mediators; Inflammatory; Insulin; Insulin Receptor; Insulin Resistance; Interleukin-6; Laboratories; Leptin; Link; Lipopolysaccharides; Liver; Lysine; Mass Spectrum Analysis; Mediating; Mediator of activation protein; Metabolic; Metabolic Diseases; Molecular; Molecular Biology; Mouse Strains; Mus; Myelogenous; Non-Insulin-Dependent Diabetes Mellitus; Nonesterified Fatty Acids; Obesity; Pathogenesis; Peripheral; Physiological; Plasmids; Population; Prevalence; Process; Protein Family; Proteins; Proteomics; Regimen; Regulation; Reporting; Research; Risk; Role; Scientific Advances and Accomplishments; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Site; TLR4 gene; TNF Receptor-Associated Factors; TNF gene; TNF receptor-associated factor 3; TRAF2 gene; Techniques; Testing; Tissues; Transcription Factor AP-1; Transgenic Mice; Tumor Necrosis Factor Receptor; Tyrosine Phosphorylation; Ubiquitination; Up-Regulation; Western Blotting; adenoviral-mediated; base; chromatin immunoprecipitation; cytokine; diabetic patient; driving force; functional outcomes; high risk; immunoregulation; in vivo; insulin receptor substrate 1 protein; insulin sensitivity; insulin signaling; member; mouse model; mutant; new therapeutic target; novel; novel strategies; novel therapeutics; overexpression; protein expression; response; transcription factor; treatment strategy; ubiquitin ligase; ubiquitin-protein ligase

Project Abstract Type 2 diabetes is the most common metabolic disease and affects nearly 10% of the American population. Given its close association with obesity, not only is the prevalence expected to increase in the future, but individuals with the disease are at a higher risk for developing severe health complications, including cardiovascular disease, which remains the leading cause of death for diabetic patients. Therefore, it is imperative that better treatment strategies are developed to manage the progression of the disease and its associated health risks. Many factors, both genetic and environmental, contribute to the manifestation of type 2 diabetes; however, the development of peripheral insulin resistance remains the strongest etiological predictor of disease progression. An abundance of scientific evidence suggests that chronic inflammation, particularly in the setting of obesity, promotes cellular insulin resistance. Specifically, pro-inflammatory cytokines are elevated in metabolic diseases and can inhibit insulin-dependent signaling pathways in tissue sites such as the liver. Recently, a unique link between a family of proteins known as the TNF receptor-associated factors (TRAFs) and the development of insulin resistance has been developed. TRAF proteins are key mediators in cytokine signaling, but their role in the liver, particularly hepatocytes, are not well defined. Preliminary data suggests that one specific member, TRAF3, negatively regulates insulin sensitivity in primary hepatocytes as well as in transgenic mouse models by promoting the ubiquitination of insulin receptor substrates 1 and 2 (IRS1/2), which function as important adaptor proteins that facilitate insulin signaling transduction pathways in target cells. Therefore, the working hypothesis of this proposal is that hepatic TRAF3 expression directly promotes insulin resistance in the liver through altered ubiquitination of IRS1/2 adaptor proteins. To test this hypothesis, two aims have been developed. Aim 1 seeks to determine the mechanisms that drive hepatic TRAF3 induction in obesity. Preliminary data suggests that TRAF3 is up-regulated in mouse models of obesity. To determine the mechanisms by which this occurs, a variety of approaches, conducted in primary hepatocytes and mouse models, will be employed to investigate the roles of cytokines, free fatty acids, and lipopolysaccharide in promoting TRAF3 up-regulation in a Toll-like and TNF receptor-dependent fashion. Aim 2 seeks to determine the molecular mechanisms by which TRAF3 promotes insulin resistance. Specifically, TRAF3's role as a ubiquitin ligase will be the focus by using transgenic mouse strains, molecular biology and analytical chemistry techniques, such as mass spectrometry, to identify the sites of IRS1/2 ubiquitination and its functional outcome in the liver. Together, these studies will advance the scientific understanding of how inflammation and IR are linked, as well as provide novel approaches and strategies to treat type 2 diabetes and its associated complications.

项目摘要 2型糖尿病是最常见的代谢疾病，影响近10%的美国人口。 鉴于其与肥胖的密切联系，不仅预计未来的患病率会增加， 患有这种疾病的人患严重健康并发症的风险更高，包括 心血管疾病，这仍然是糖尿病患者死亡的主要原因。因此有 当务之急是开发更好的治疗策略来控制疾病的进展及其 相关的健康风险。许多因素，包括遗传和环境，都有助于2型糖尿病的表现。 糖尿病;然而，外周胰岛素抵抗的发展仍然是最强的病因学预测因子 疾病的发展。大量的科学证据表明，慢性炎症，特别是在 肥胖症的形成，促进了细胞胰岛素抵抗。具体来说，促炎细胞因子是 在代谢性疾病中升高，并可抑制组织部位（如 肝脏最近，一个独特的连接蛋白质家族称为肿瘤坏死因子受体相关因子 （TRAFs）和胰岛素抵抗的发展已经发展。TRAF蛋白是细胞凋亡的关键介质， 细胞因子信号传导，但它们在肝脏，特别是肝细胞中的作用还没有很好的定义。初步数据 表明一个特定的成员TRAF3负调节原代肝细胞中的胰岛素敏感性， 通过促进胰岛素受体底物1和2的泛素化， (IRS1/2），其作为重要的衔接蛋白，促进胰岛素信号转导途径， 靶细胞因此，该建议的工作假设是肝TRAF 3表达直接与肝细胞凋亡相关。 通过改变IRS1/2接头蛋白的泛素化促进肝脏中的胰岛素抵抗。为了验证这一 假设，两个目标已经制定。目的1旨在确定驱动肝细胞凋亡的机制。 肥胖中的TRAF3诱导。初步数据表明，TRAF3在肥胖小鼠模型中上调。 为了确定这种情况发生的机制，在初级阶段进行了各种方法， 肝细胞和小鼠模型，将用于研究细胞因子，游离脂肪酸， 脂多糖以Toll样和TNF受体依赖的方式促进TRAF3上调。目的2 试图确定TRAF3促进胰岛素抵抗的分子机制。具体地说， TRAF3作为一种泛素连接酶的作用将成为利用转基因小鼠品系、分子生物学和分子生物学方法研究的焦点。 分析化学技术，如质谱，以确定IRS 1/2泛素化的位点， 它在肝脏中的功能结果。总之，这些研究将促进科学的理解， 炎症和IR是相关的，并提供了治疗2型糖尿病的新方法和策略 及其相关并发症。