Redox-and acetylation-dependent control of vascular tone

描述（由申请人提供）：内皮型一氧化氮合酶（eNOS）的翻译后修饰在调节eNOS活性、内皮型一氧化氮（NO）产生、内皮依赖性血管舒张和血管张力中起着非常重要的作用。磷酸化、酰化和糖基化在调节eNOS活性中的作用是公认的。然而，乙酰化的重要性，作为一种翻译后修饰，在管理eNOS活性尚未仔细研究。 基于新的初步证据，本申请提出eNOS在内皮中被乙酰化，并且eNOS的位点特异性去乙酰化在控制eNOS活性、内皮依赖性血管舒张和血管张力中具有重要作用。我们认为，普遍表达的蛋白脱乙酰酶SIRT 1（沉默信息调节器），通过脱乙酰化eNOS在特定的乙酰化赖氨酸残基，刺激eNOS活性，内皮NO的生产，并促进内皮依赖性血管舒张。本申请将检查eNOS是否是SIRT 1的直接靶点，并详细描述SIRT 1刺激eNOS活性的机制。将评估SIRT 1依赖性机制在管理内皮依赖性血管舒张中的重要性，以及eNOS在该机制中的介导作用。将确定SIRT 1与调节血管张力的生理变化的体内相关性。最后，涉及p53转录因子及其转录共激活因子氧化还原因子-1的氧化还原敏感性转录机制对人SIRT 1表达的调节，以及这种转录机制在调节血管SIRT 1表达中的生理重要性，将被探讨。 总之，本申请将确定eNOS是否是SIRT 1去乙酰化酶的靶点，并且在这样做的过程中，有望定义一种调节内皮依赖性血管舒张的新机制。它还将探讨这种机制在体内控制血管张力的生理重要性。因此，它可能为治疗人类内皮功能障碍和血管张力失调提供新的靶点和策略。 血管中一氧化氮的产生是调节血管功能的一种非常重要的手段。该项目研究了一种控制血管中一氧化氮产生的新方法。了解这种控制血管中一氧化氮的新机制将有助于我们进一步了解高血压和动脉粥样硬化等疾病状态下的血管如何具有较低的一氧化氮水平。

DESCRIPTION (provided by applicant): Post-translational modifications of endothelial nitric oxide synthase (eNOS) play a very important part in regulating eNOS activity, endothelial nitric oxide (NO) production, endothelium-dependent vasorelaxation, and vascular tone. The roles of phosphorylation, acylation, and glycosylation in regulating eNOS activity are well recognized. However, the importance of acetylation, as a post-translational modification, in governing eNOS activity has not been carefully studied. Based on novel preliminary evidence, this application proposes that eNOS is acetylated in the endothelium, and site-specific de-acetylation of eNOS has an important role in governing eNOS activity, endothelium-dependent vasorelaxation, and vascular tone. We suggest that the ubiquitously expressed protein deacetylase SIRT1 (Silent Information RegulaTor), by de-acetylating eNOS at specific acetylated lysine residues, stimulates eNOS activity, endothelial NO production, and promotes endothelium-dependent vasorelaxation. This application will examine if eNOS is a direct target of SIRT1, and characterize in detail the mechanism through which SIRT1 stimulates eNOS activity. The importance of a SIRT1-dependent mechanism in governing endothelium-dependent vascular relaxation, and the mediating role of eNOS in this mechanism, will be assessed. The in vivo relevance of SIRT1 with respect to modulation of physiologic changes in vascular tone will be determined. Finally, the regulation of human SIRT1 expression by a redox-sensitive transcriptional mechanism involving the p53 transcription factor and its transcriptional co-activator redox factor-1, and the physiologic importance of this transcriptional mechanism in regulating vascular SIRT1 expression, will be explored. In summary, this application will determine if eNOS is a target of the SIRT1 deacetylase, and in doing so, promises to define a novel mechanism for the regulation of endothelium-dependent vascular relaxation. It will also explore the physiologic importance of this mechanism in controlling vascular tone in vivo. As such, it may offer new targets and strategies for the treatment of human disorders of endothelial function and dysregulation of vascular tone. PUBLIC HEALTH RELEVANCE Production of nitric oxide in blood vessels is a very important means for the regulation of blood vessel function. This project examines a novel means by which production of nitric oxide in blood vessels is controlled. Understanding this new mechanism that controls nitric oxide in blood vessels will help further our knowledge about how blood vessels in disease states such as high blood pressure and atherosclerosis have lower levels of nitric oxide.