Differentiation of mitochondrial vs. nuclear function of telomerase

描述(申请人提供)：端粒酶，一种核糖核蛋白，可以对抗端粒缩短，最近被认为具有端粒独立的生存功能。在氧化应激条件下，端粒酶对线粒体功能的保护作用已被描述，但与线粒体或核TERT(端粒酶催化亚单位)相关的确切机制和表型尚不清楚。我们已经证明，在存在冠状动脉疾病或急性血管应激源的情况下，血流介导的扩张(FMD)机制从NO转变为H_2O_2。本研究旨在区分核TERT和线粒体TERT在心血管疾病发展中的作用。在我们的中心假说中，线粒体TERT在减少线粒体活性氧物种(ROS)从而保护心血管疾病和其他ROS相关疾病方面发挥着关键的、以前未被发现的作用。本研究以心血管健康为研究对象，以FMD及其机制和氧化还原环境为生理标记物。被测试的概念范式转变是线粒体TERT通过改善线粒体呼吸链活性来减少线粒体ROS的产生。这有助于维持正常的NO水平，从而维持微血管中FMD的生理调节。相反，我们假设线粒体TERT减少会导致线粒体ROS增加，通过将FMD的介质从NO改变为H_2O_2来驱动微血管功能障碍，从而创造一个促炎环境。我们将使用最先进的方法来评估血管的反应性，并对氧化还原环境进行分子评估，以表征端粒酶在调节细胞和线粒体ROS水平中的作用。这一新的假设和生成的模型具有重要的翻译潜力，对于研究不同疾病和多个领域的研究人员将非常有用。

DESCRIPTION (provided by applicant): Telomerase, a ribo-nucleoprotein that counteracts telomere shortening, has recently been suggested as having a telomere independent survival function. A protective effect of telomerase on mitochondrial function under conditions of oxidative stress has been described, yet the exact mechanism and phenotype linked to mitochondrial or nuclear TERT (catalytic subunit of telomerase) is not clearly identified. We have shown that in the presence of coronary artery disease or acute vascular stressors, there is a shift in the mechanism of flow mediated dilation (FMD) from NO to H2O2. The current study aims to differentiate the role of nuclear TERT vs. mitochondrial TERT in the development of cardiovascular (CV) disease. In our central hypothesis, mitochondrial TERT plays a critical and previously undiscovered role in reducing mitochondrial reactive oxygen species (ROS) thus protecting against CV disease and other ROS associated disorders. This study will focus on CV health and use FMD and its mechanism and redox environment as physiological markers. The conceptual paradigm shift tested is that mitochondrial TERT decreases mitochondrial ROS production by improving mitochondrial respiratory chain activity. This contributes to maintaining normal NO levels, thereby preserving physiological regulation of FMD in the microvasculature. Conversely, we postulate that reduced mitochondrial TERT results in increased mitochondrial ROS, driving microvascular dysfunction by changing the mediator of FMD from NO to H2O2 thereby creating a pro-inflammatory milieu. We will be using state of the art methods to evaluate vascular reactivity alongside molecular evaluation of the redox environment to characterize the role of telomerase in regulating cellular and mitochondrial ROS levels. This novel hypothesis and the models generated have important translational potential and will be extremely useful for investigators studying varying diseases and in multiple fields.