IKKBeta Mediated Impairment of Endothelial Nitric Oxide Production

IKKβ 介导的内皮一氧化氮生成损伤

• 批准号: 7269389
• 负责人: Francis Kim
• 金额: $ 26.96万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7269389
• 关键词: 1-Phosphatidylinositol 3-Kinase; Address; Adult; Agonist; Animals; Aspirin; Atherosclerosis; Attenuated; Biological Availability; Blood Vessels; Bone Marrow Transplantation; Bradykinin; Cardiovascular Diseases; Cause of Death; Cells; Data; Development; Diabetes Mellitus; Diabetic Angiopathies; Diet; Dominant-Negative Mutation; Endothelial Cells; Enzymes; Fatty acid glycerol esters; Functional disorder; Genetic; Glucose; Goals; Immune; Impairment; Individual; Inflammatory; Insulin; Insulin Resistance; Laboratories; Lipopolysaccharides; Liquid substance; Mediating; Mediator of activation protein; Modeling; NF-kappa B; Natural Immunity; Nitric Oxide; Nonesterified Fatty Acids; Nutrient; Obesity; Pathogenesis; Pathway interactions; Patients; Phosphoinositide-3-Kinase, Catalytic, Gamma Polypeptide; Phosphorylation; Physiological; Play; Production; Protein Overexpression; Regulation; Research; Research Personnel; Research Proposals; Risk Factors; Role; Serine; Signal Transduction; Stimulus; Testing; Therapeutic; Toll-Like Receptor Pathway; Toll-like receptors; Tumor Necrosis Factor-alpha; base; cytokine; disability; feeding; human TNF protein; in vivo; in vivo Model; insulin signaling; mortality; mouse model; mouse toll-like receptor 4; programs; reconstitution; research study; response; shear stress; toll-like receptor 4; vascular inflammation

Description (provided by applicant): Cardiovascular disease is the principal cause of death and disability in adults with diabetes. Endothelial dysfunction is a hallmark of diabetic vascular disease and is characterized by decreased bioavailability of nitric oxide (NO). Our long-term goal is to elucidate the mechanism by which insulin resistance reduces NO production in endothelial cells and thereby facilitate the development of therapeutics that can be used to attenuate the impact of diabetes and insulin resistance on cardiovascular disease. The specific hypothesis of this revised research proposal is that IKKbeta a key enzyme in the regulation of the NF-kappaB inflammatory pathway mediates the effect of insulin resistance on NO production. This hypothesis is based on the following experimental observations completed in our laboratory. First, IKKbeta is activated in endothelial cells by free fatty acids (FFA), high glucose, and TNF-alpha all of which have been implicated in the pathogenesis of insulin resistance. Second, activation of IKKbeta is associated with impaired NO production. Third, inhibition of IKKbeta pharmacologically using aspirin or genetically using a dominant negative IKKbeta construct blocks the ability of FFA, TNF-alpha, or glucose to impair NO production. Finally, overexpression of wild-type IKKbeta recapitulates the effect of FFA, glucose, or TNF-alpha to impair NO production. The results of these experiments suggest that IKKbeta activation is both necessary and sufficient to cause impairment of endothelial NO production. These results also indicate that inflammatory pathways play a key role in both nutrient excess and cytokine mediated endothelial insulin resistance. Based on these observations the experimental focus of this proposal is on the role of IKKbeta in mediating impaired NO production. We propose to determine how activation of IKKbeta impairs endothelial NO production in both an endothelial cell culture model and in an in vivo model of insulin resistance. We will next address how mediators of insulin resistance might activate IKKbeta and examine a potential role for innate immunity (Toll Like Receptor) in mediating vascular insulin resistance. The following aims are proposed: Aim 1. To determine the mechanism by which IKKbeta activation impairs NO production in endothelial cells. Aim 2. To determine whether impaired endothelial insulin signaling and NO production are associated with IKKbeta activation in vivo in a mouse model of diet-induced obesity and insulin resistance. Aim 3. To determine whether the Toll Like Receptor pathway is necessary for endothelial activation of IKKbeta during the development of vascular insulin resistance.

描述（由申请人提供）：心血管疾病是成年糖尿病患者死亡和残疾的主要原因。内皮功能障碍是糖尿病血管疾病的标志，其特征在于一氧化氮（NO）的生物利用度降低。我们的长期目标是阐明胰岛素抵抗降低内皮细胞NO生成的机制，从而促进可用于减轻糖尿病和胰岛素抵抗对心血管疾病影响的治疗方法的开发。这项修订的研究建议的具体假设是，IKK β，在NF-κ B炎症通路的调节的关键酶介导的影响，胰岛素抵抗的NO生产。这一假设是基于我们实验室完成的以下实验观察。首先，IKK β在内皮细胞中被游离脂肪酸（FFA）、高糖和TNF-α激活，所有这些都与胰岛素抵抗的发病机制有关。其次，IKK β的激活与NO产生受损相关。第三，使用阿司匹林或遗传上使用显性阴性IKK β构建体抑制IKK β抑制剂阻断FFA、TNF-α或葡萄糖损害NO产生的能力。最后，野生型IKK β的过度表达再现了FFA、葡萄糖或TNF-α损害NO产生的作用。这些实验的结果表明，IKK β激活是必要的，并足以导致内皮NO的生产障碍。这些结果还表明，炎症途径在营养过剩和细胞因子介导的内皮胰岛素抵抗中起关键作用。基于这些观察结果，本建议的实验重点是IKK β在介导受损NO产生中的作用。我们建议在内皮细胞培养模型和胰岛素抵抗的体内模型中确定IKK β的激活如何损害内皮NO的产生。接下来我们将讨论胰岛素抵抗的介质如何激活IKK β，并研究先天免疫（Toll样受体）在介导血管胰岛素抵抗中的潜在作用。提出了以下目标：目标1。确定IKK β激活损害内皮细胞NO生成的机制。目标二。在饮食诱导的肥胖和胰岛素抵抗小鼠模型中，确定受损的内皮胰岛素信号传导和NO产生是否与体内IKK β激活相关。目标3。确定Toll样受体通路是否是血管胰岛素抵抗发生过程中内皮激活IKK β所必需的。