"0-GlcNAcylation and Cardioprotection"

说明）： 最近，O-连接的p-N-修饰的核，线粒体和细胞质蛋白质， 乙酰葡糖胺（0-GlcNAc）已经作为应激反应和细胞存活的新型调节剂出现。 许多形式的细胞损伤，包括心脏缺血预处理（急性和长期），导致 在体内和体外模型中，O-GlcNAc水平升高。升高0-GlcNAc酰化之前，或 在缺血再灌注损伤模型中， 如热应激、氧化应激、内质网应激、缺氧和创伤出血。在一起， 这些数据表明0-GlcNAc是一种新的内源性心脏保护剂。然而，分子 0-GlcNAc调节蛋白质功能的机制，导致细胞存活增强， 心脏保护尚未确定。这项研究的长期目标是确定一种分子， 水平0-GlcNAc促进细胞存活的机制。本申请的目的是： 1)定义0-GlcNAc在介导缺血预处理中的作用。为了 表征0-GlcNAc导致心脏保护的机制，蛋白质动态 O-GlcNAc对缺血预处理的反应被修饰， 导致增强的0-GlcNAc酰化。 2)阐明0-GlcNAc调节以下过程的分子机制 自噬导致心脏保护。来描述 0-GlcNAc通过自噬保护心肌细胞，我们将定义：1）0-GlcNAc在心肌细胞自噬中的作用。 在缺血预处理期间诱导自噬; 2）如果增强的自噬对于0- GlcNAc介导的心脏保护; 3）直接参与自噬的蛋白质的身份（或 调节自噬），其由O-GlcNAc修饰和调节。 总之，这些研究将描述一种新的心脏内源性防御机制，强调 开发增强心脏缺血耐受性的替代策略的新靶点 再灌注损伤 相关性（参见说明）： 糖0-GlcNAc是细胞应激反应的关键组分，其增强细胞和细胞外基质的能力。 组织存活缺血再灌注损伤（例如，心脏病发作），但O- GlcNAc保护细胞是未知的。我们的目标是了解0-GlcNAc如何促进细胞存活， 在分子水平上建立缺血再灌注损伤模型，从而确定开发的新靶点 增强心脏对缺血再灌注损伤的耐受性的替代策略。

instnjctions): Recently, the modification of nuclear, mitochondrial, and cytoplasmic proteins by O-linked p-N- acetylglucosamine (0-GlcNAc) has emerged as a novel regulator of the stress response and cell survival. Numerous forms of cellular injury, including cardiac ischemic preconditioning (acute and prolonged), lead to elevated levels of 0-GlcNAc in both in vivo and in vitro models. Elevating 0-GlcNAcylation before, or immediately after, the induction of cellular injury is protective in models of ischemia reperfusion injury, as well as heat stress, oxidative stress, endoplasmic reticulum stress, hypoxia, and trauma hemorrhage. Together, these data suggest that 0-GlcNAc is a novel endogenous cardioprotective agent. However, the molecular mechanisms by which 0-GlcNAc regulates protein function leading to enhanced cell survival and cardioprotection have not been identified. The long term goal of this investigator, is to identify at a molecular level the mechanisms by which 0-GlcNAc promotes cell survival. The objective of this application is to: 1) Define the role(s) of 0-GlcNAc in mediating ischemic preconditioning. In order to characterize the mechanisms by which 0-GlcNAc leads to cardioprotection, proteins dynamically O-GlcNAc modified in response to ischemic-preconditioning will be identified and pathways that lead to enhanced 0-GlcNAcylation will be defined. 2) Elucidate the molecular mechanism(s) by which 0-GlcNAc regulates the process of autophagy leading to cardioprotection. To characterize the molecular mechanisms by which 0-GlcNAc protects cardiomyocytes via autophagy we will define: 1) the role of 0-GlcNAc in inducing autophagy during ischemic preconditioning; 2) if enhanced autophagy is critical for 0- GlcNAc mediated cardioprotection; 3) the identity of proteins involved directly in autophagy (or regulating autophagy) that are modified and regulated by 0-GlcNAc. Together, these studies will characterize a novel endogenous defense mechanism of the heart, highlighting new targets for the development of alternative strategies that enhance the hearts tolerance to ischemia reperfusion injury. RELEVANCE (See instructions): The sugar 0-GlcNAc is a key component of the cellular stress response that enhances the ability of cells and tissues to survive ischemia reperfusion injury (for example, heart attack), but the mechanisms by which O- GlcNAc protects cells are unknown. Our goal is to understand how 0-GlcNAc promotes cell survival in a model of ischemia reperfusion injury at the molecular level, thus identifying new targets for the development of alternative strategies to enhance the heart's tolerance to ischemia reperfusion injury.