Period in Cardio Protection

描述(由申请者提供)：这个为期5年的培训计划提出了在心肌缺血和心脏生物学领域作为独立生物医学研究人员的职业发展计划。首席研究员，是一名委员会认证的麻醉师，并已完成重症监护团契培训。在赞助商和经验丰富的合作者的帮助下，他将扩展自己的科学技能，为成为一名独立的内科科学家的职业发展做准备。该计划将侧重于使用体外(暴露于低氧的分离心肌细胞)和体内(小鼠原位心肌缺血)模型的心肌细胞功能和缺血适应过程调节的细胞内途径的分子生物学技能。为了提高他在代谢生物学方面的知识，他将参加由丹佛国家犹太人组织的欧米克技术项目提供的课程。托马斯·亨索恩，医学博士，部门负责人将提供赞助。器官缺氧和缺血的国际分子生物学专家Holger Eltzschig医学博士将担任专门的导师并提供赞助。该计划将受益于肖恩·科尔根博士的合作专业知识，他是导致适应低氧的分子机制方面的世界专家，他将为细胞内途径、翻译后机制和代谢研究提供咨询支持。此外，彼得·巴特里克医学博士和迈克尔·布里斯托医学博士都是世界知名的心脏病专家，他们将每16周与Eltzschig博士和Colgan博士在一个咨询委员会中合作并提供服务。该委员会将审查进展情况，并提供密切的科学支持和职业建议。心肌缺血(MI)是一个永久性且严重的医学问题。在过去的几十年里，令人信服的证据表明，腺苷的产生在心脏缺血预适应(IP)的信号转导中起着核心作用，这种现象被称为体内最强的心肌缺血保护形式。因此，许多可能的效应器已被确定为对心脏IP起关键作用。然而，IP启动的途径是完全未知的。在这项研究中，我们提供了来自微阵列的数据，其中我们鉴定了两个昼夜节律蛋白，周期1和周期2，作为腺苷依赖分子。在后者中，我们可以证实IP和腺苷依赖对这两种节律蛋白的诱导和稳定。在PER2-/-小鼠身上的后续研究揭示了周期在心脏缺血和缺血中的功能作用。PER2-/-小鼠的心肌梗死面积更大，IP介导的心肌保护作用消失。由于昼夜节律蛋白在代谢过程中起主导作用，并被报道控制线粒体的代谢，我们接下来对线粒体中的主要耗氧酶--ATP合成酶进行研究。我们发现，该酶在野生型小鼠中由于IP而下调，但在周期缺陷小鼠中没有下调。基于这些发现，我们假设周期调节代谢组织适应，而代谢组织适应是心脏IP的核心。设计了三个具体的目标来解决MI中时期的新角色。(1)在第一个目标中，我们建议结合药理学和遗传学的方法来研究体外周期稳定的调节机制和后果。(2)在第二个目标中，我们将结合体外和体内研究来研究由周期稳定启动的代谢途径。在第三个目标中，通过对组织特异性小鼠的长期利用，我们将首先阐明内皮细胞和心肌细胞在体内对MI的个体贡献。最后，我们将以心脏中的时间段作为治疗选择，使用强光照射治疗MI。这些研究旨在阐明心肌梗死期间调节细胞损伤的内源性途径。以这种途径为靶点将为治疗心肌梗塞的新的和具体的治疗方法奠定基础，这是改善发病率和死亡率所迫切需要的。

DESCRIPTION (provided by applicant): This 5-year training program proposes the development plan for a career as an independent biomedical researcher in the area of myocardial ischemia and cardiac biology. The principal investigator, is a board certified Anesthesiologist and has completed a Critical Care Fellowship training. With the sponsors and experienced collaborators he will expand on his scientific skills in preparation for career progression as an independent physician-scientist. The program will emphasize skills in molecular biology of intracellular pathways in myocyte function and regulation of ischemia- adaptive processes using in vitro (isolated myocytes exposed to hypoxia) and in vivo (murine in situ myocardial ischemia) models. To advance his knowledge in metabolic biology he will attend courses offered by the Omics Technologies Program at the National Jewish, Denver. Thomas Henthorn, MD, the Departmental Head will provide sponsorship. Holger Eltzschig MD, PhD, an international expert in molecular biology of organ hypoxia and ischemia will be the dedicated mentor and provide sponsorship. The program will benefit from collaborative expertise of Sean Colgan PhD, a world expert in molecular mechanisms leading to adaptation to hypoxia, who will provide consultative support for the studies on intracellular pathways, posttranslational mechanisms and metabolic studies. Additionally, Peter Buttrick, MD and Michael Bristow MD, PhD, both world renowned cardiologists, will collaborate and serve with Drs. Eltzschig and Colgan on an advisory committee every 16 weeks. This committee will review progress and provide close scientific support and career advice. Myocardial ischemia (MI) is a permanent and serious medical problem. Over the last decades, convincing evidence has demonstrated a central role of adenosine generation in signaling in cardiac ischemic preconditioning (IP), a phenomenon known as the strongest in vivo-form of protection against myocardial ischemia. As such, many possible effectors have been identified to be critical for mediating IP of the heart. However, the pathway initiated by IP is completely unknown. In this study, we present data from a microarray where we identified two circadian rhythm proteins, Period 1 and Period 2, as adenosine dependant molecules. In the latter we could confirm an IP and adenosine dependant induction and stabilization of these two rhythm proteins. Following studies in Per2-/- mice revealed a functional role of Period in IP and ischemia of the heart. Per2-/- mice had bigger infarct sizes and abolished cardioprotection mediated by IP. Since circadian rhythm proteins are known to play a dominant role in metabolic processes and are reported to control mitochondrial metabolism, we next pursued studies on the main oxygen consuming enzyme in mitochondria, the ATP Synthase. We found that this enzyme was downregulated due to IP in wildtype, but not in Period deficient mice. Based on these findings we hypothesize that Periods mediate metabolic tissue adaptation which is central to cardiac IP. Three specific aims were designed to address novel roles for Period in MI. (1) In the first aim, we propose to study regulatory mechanisms and consequences of Period stabilization in vitro by combining pharmacological and genetic approaches. (2) In the second aim, we will combine in vitro and in vivo studies to investigate metabolic pathways initiated by period stabilization. In the third aim, by utilizing tissue specific mice for Period, we will first elucidate the individual contribution of endothelium and cardiomyocytes to MI in vivo. Finally, we will target Period in the heart as therapeutic option to treat MI using intense light exposure. These studies are designed to shed new light on endogenous pathways that regulate cell injury during MI. Targeting such pathways will lay the groundwork for novel and specific therapeutic approaches in the treatment of MI, which are urgently needed to improve morbidity and mortality.