Mechanisms of Caloric Restriction and Mimetic Vasoprotection in Old Arteries

描述（由申请人提供）：年龄增长与动脉功能障碍的发展有关，其特征为内皮功能障碍和大动脉僵硬。一种假设是，长期减少热量摄入（热量限制；CR）可以激活细胞和分子事件，防止与年龄相关的动脉功能障碍。本研究旨在确定终身热量限制（40%）和/或药理学热量限制模拟是否可以预防与年龄相关的动脉功能障碍以及可能发生这种情况的细胞和分子机制。具体来说，我们将研究终身CR对参与调节中年（MA）和老年(O)小鼠动脉氧化应激、炎症和凋亡的核转录因子的调节和调节的影响。具体目的是：(1)测量内皮依赖性扩张（EDD）、一氧化氮（NO）生物利用度和MA/O小鼠大动脉硬度，并确定年龄增长是否与促氧化、促炎症和促凋亡表型相关；(2)确定CR是否减弱促氧化、促炎症和促凋亡信号分子的激活和乙酰化；核因子κ B （NFkB）、p53和叉头foxO （FoxO3a）通过增加MA/O小鼠的核去乙酰化酶SIRT-1和(3)确定核去乙酰化酶SIRT-1的激活是否可以预防老化动脉表型和功能障碍。为此，我们将研究年轻（Y: 4-6个月），MA（18-20个月）和O（29-31个月）雄性B6D2F1小鼠。将测量内皮功能、一氧化氮生物利用度和大动脉硬度。将在主动脉裂解物和内皮细胞中评估氧化应激、炎症细胞因子、凋亡标志物和NFkB、p53和FoxO3a的激活/乙酰化。最后，我们将利用核去乙酰化酶SIRT-1的药理抑制来确定其在年龄和热量限制相关的动脉功能、氧化应激、炎症和细胞凋亡中的作用。预期的结果将为CR和CR模拟物保存与年龄相关的动脉功能的细胞和分子机制提供新的见解。

DESCRIPTION (provided by applicant): Advancing age is associated with the development of arterial dysfunction characterized by endothelial dysfunction and large artery stiffness. One hypothesis is that the chronic reduction of caloric intake (Caloric Restriction; CR) can activate cellular and molecular events that prevent age-related arterial dysfunction. This proposal aims to determine if lifelong caloric restriction (40%) and/or a pharmacological caloric restriction mimetic can prevent the age-related arterial dysfunction and the cellular and molecular mechanisms by which this may occur. Specifically, we will examine the effect of lifelong CR on the regulation and modulation of nuclear transcription factors, by acetylation, involved in the regulation of arterial oxidative stress, inflammation and apoptosis in middle-aged (MA) and older (O) mice. The specific aims are (1) to measure endothelium dependent dilation (EDD), nitric oxide (NO) bioavailability and stiffness in large arteries of MA/O mice and to determine if advancing age is associated with a pro-oxidative, -inflammatory, -apoptotic phenotype, (2) to determine if CR attenuates the activation and acetylation of the pro- oxidative, -inflammatory and -apoptotic signaling molecules; nuclear factor kappa B (NFkB), p53, and forkhead foxO (FoxO3a) via an increase a nuclear deacetylase SIRT-1 in MA/O mice and (3) to determine if activation of the nuclear deacetylase SIRT-1 can prevent the aged arterial phenotype and dysfunction. To do so, we will study young (Y: 4-6 mo), MA (18-20 mo) and O (29-31 mo) male B6D2F1 mice. Endothelial function, nitric oxide bioavailability, and larger artery stiffness will be measured. Oxidative stress, inflammatory cytokines, markers of apoptosis and activation/acetylation of NFkB, p53 and FoxO3a will be assessed in aortic lysates and endothelial cells. Lastly, we will utilize pharmacological inhibition of the nuclear deacetylase SIRT-1 to determine its role in age and caloric restriction-associated arterial function, oxidative stress, inflammation and apoptosis. The expected results will provide novel insight into the cellular and molecular mechanisms by which CR and CR mimetics preserve age-associated arterial function.