Mechanisms of NAMPT-stimulated nitric oxide release at the myoendothelial junctio

NAMPT 刺激肌内皮连接处一氧化氮释放的机制

• 批准号: 7912368
• 负责人: Adam Carl Straub
• 金额: $ 5.05万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-10 至 2011-09-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7912368
• 关键词: Blood Pressure; Cardiovascular system; Caveolae; Communication; Coupled; Disease; Endothelial Cells; Endothelium; Event; Goals; In Vitro; Insulin Receptor; Niacinamide; Nitric Oxide; Phosphorylation; Play; Post-Translational Protein Processing; Protein Analysis; Proteomics; Regulation; Reporting; Research; Resistance; Role; Signal Transduction; Smooth Muscle Myocytes; Vascular Endothelial Cell; Vasomotor; blood pressure regulation; human NOS3 protein; in vivo; knockout animal; prevent; public health relevance; response; vasomotion

DESCRIPTION (provided by applicant): Mechanisms of NAMPT-stimulated nitric oxide release at the myoendothelial junction Communication between endothelial cells (ECs) and smooth muscle cells (SMCs) is imperative for blood pressure regulation and vasomotor responses in the resistance vasculature. The myoendothelial junction (MEJ) is unique to the resistance vasculature and is hypothesized to be a highly organized cell-signaling microdomain that can regulate crosstalk between ECs and SMCs. Recently, caveolae were identified at the MEJ, providing circumstantial evidence that unique signaling events at this juncture. Additionally, numerous reports have demonstrated that caveolae regulate endothelial nitric oxide synthase (eNOS) transport and activity. These discoveries led us to hypothesize that eNOS synthase may polarize to the MEJ and is compartmentalized to promote highly localized cell signaling. Our preliminary results confirm that eNOS localizes to the MEJ and is selectively phosphorylated at the MEJ in vitro. To identify potential activators of eNOS, we performed a proteomic analysis of proteins that were enriched at the MEJ and found nicotinamide phoshoribosyltransferase (NAMPT). Importantly, NAMPT is a recently characterized adipokine that can stimulate eNOS phosphorylation, nitric oxide release, and endothelium dependent vasodialation. The mechanisms by which NAMPT can activate eNOS remain unclear, however it has been suggested that the insulin receptor- 2, which also polarizes to the MEJ, plays an intermediary role. Therefore, the aim of this proposal is to identify mechanisms of NAMPT regulated nitric oxide release at the MEJ, with a particular focus on understanding localized nitric oxide signaling at the MEJ Specifically, the goals of this proposal are to; 1.) define localized expression of eNOS, IR-2, and NAMPT at the MEJ and post-translational modifications, 2.) understand the mechanism of NAMPT stimulated eNOS signaling at the MEJ, 3) generate a NAMPT/EC specific IR-2 knockout animal to determine in vivo mechanisms of blood pressure and vasomotion regulation. This research plan has the additional benefit of providing an investigational framework upon which pharmacological studies of compartmentalized NAMPT/eNOS signaling at the MEJ may be performed, with the long term aim of preventing and or reversing cardiovascular related diseases. PUBLIC HEALTH RELEVANCE: Within the resistance vasculature endothelial cells and vascular smooth muscle cells are coupled in part by myoendothelial junctions (MEJ). The focus of this proposal entails the compartmentalization and function of endothelial nitric oxide synthase (eNOS) and nicotinamide phoshoribosyltransferase (NAMPT) at the MEJ. We will attempt to elucidate the interaction between NAMPT and eNOS as well as the potential implications this may have on the regulation of blood pressure and vasomotion.

描述（由申请人提供）：NAMPT刺激的一氧化氮机制在内皮细胞（ECS）和平滑肌细胞（SMC）之间释放的一氧化氮释放（SMC）对于血压调节和阻力脉管中的血压调节和血管肌瘤反应至关重要。肌膜内皮结（MEJ）是抗性脉管系统独有的，被认为是一个高度有组织的细胞信号微域，可以调节EC和SMC之间的串扰。最近，在MEJ上确定了小窝，提供了间接证据，表明此关头处于该关头的独特信号事件。此外，许多报告表明，小窝调节内皮一氧化氮合酶（ENOS）的运输和活性。这些发现使我们假设eNOS合酶可能偏振与MEJ，并被划分以促进高度局部的细胞信号传导。我们的初步结果证实了ENOS定位于MEJ，并在MEJ体外有选择地磷酸化。为了鉴定eNOS的潜在活化剂，我们对富含MEJ的蛋白质分析进行了蛋白质组学分析，并发现了烟酰胺phoshoribosylybosylybosylybosylybosylybosylyslansferase（NAMPT）。重要的是，NAMPT是一种最近表征的脂肪因子，可以刺激eNOS磷酸化，一氧化氮释放和依赖于内皮的血管扩张。 NAMPT可以激活eNOS的机制尚不清楚，但是已经提出，胰岛素受体2（也使MEJ偏振）起中介作用。因此，该提案的目的是确定NAMPT调控一氧化氮在MEJ处的机制，特别着重于理解MEJ的局部一氧化氮信号传导，该提议的目标是： 1.）在MEJ和翻译后修饰处定义eNOS，IR-2和NAMPT的局部表达，2。）了解NAMPT的机制刺激MEJ处的ENOS信号，3）3）生成NAMPT/EC特定的IR-2敲除动物，以确定血压和血压调节的体内机制。该研究计划具有提供研究框架的其他好处，可以在MEJ上对隔室化的NAMPT/ENOS信号进行药理学研究，以防止和/或逆转心血管相关疾病的长期目的。 公共卫生相关性：在抗性血管内皮细胞和血管平滑肌细胞中，部分由肌膜内皮连接（MEJ）耦合。该提案的重点包括MEJ在MEJ上的内皮一氧化氮合酶（ENOS）和烟酰胺Phoshoribosylyslansferase（NAMPT）的隔室化和功能。我们将尝试阐明NAMPT和ENOS之间的相互作用，以及这可能对调节血压和血管症的潜在影响。