The role of energy regulation in the epithelial cell response to sepsis and the origin of multiple organ dysfuntion

项目摘要 严重脓毒症是一种综合征，估计影响美国75万人， 全世界的人每年。随着发病率的上升，死亡率超过20%，并造成重大的莫尔， 在幸存者中，败血症今天被认为是一个公共卫生问题。尽管死亡率一直在上升- 脓毒症引起多器官功能障碍的机制与器官功能障碍的增加有关， 功能障碍还没有得到很好的理解，因此治疗仍然是反应性的，而不是预防性的， 特定.最近的证据挑战了以前对脓毒症引起的器官功能障碍的理解， 由于血流减少引起的细胞死亡，例如急性肾损伤（阿基） 发生在正常或增加肾血流量的情况下;并且其特征不是急性肾小管 坏死或凋亡，而是由肾小管上皮细胞（TEC）的斑片状异质区域氧化 压力和能量消耗。细胞凋亡和坏死的缺乏，以及对代谢性再狭窄的认识， 对炎症损伤的反应不仅可以限制急性期的细胞死亡，还可以重新编程能量。 调节途径，以确定未来的反应上皮细胞，表明探索这些机制， anisms代表潜在的治疗机会。因此，本提案的目标是确定 上皮细胞重新编程代谢以适应炎性损伤的机制， 经受住这些修饰对细胞和器官功能以及细胞存活的影响。拟议研究 将在两个具体目标的框架内利用细胞培养和动物模型制定计划。目标1将阻止- 挖掘AMPK在调节TEC对脓毒症反应的糖酵解和适应性阶段中的作用。目的2 将剖析线粒体自噬作为一种能量保存反应的作用，以限制TEC氧化应激和细胞死亡 这项研究计划将在职业发展计划的背景下进行，该计划将在 以下页面，这是支持三个基本领域：指导，课程和研究。 该计划在匹兹堡大学提供的独特环境中发展，将使 主要研究者（PI）完成向独立性过渡所需的关键培训，重点是1. 脓毒症器官功能障碍转化模型系统的设计与开发; 2.的 定量上皮细胞能量调节途径（AMPK），能量利用和周转，以及线粒体- 败血症期间的药物质量控制过程;以及3.基本的荧光和活体显微技术- 评估活体动物病理生理过程的方法。这些实验将使 未来工作的阶段，以表征将能量调节与器官功能障碍联系起来的特定途径， 利用操纵这些途径的可能性来开发诊断、预防和治疗战略， 在R 01资助的项目中。最终，本职业发展计划的执行将使 PI作为脓毒症研究的未来领导者，以改善危重患者的护理。 .

PROJECT ABSTRACT Severe sepsis is a syndrome estimated to affect 750,000 people in the United States and about 19 million people worldwide every year. With a rising incidence, death rates exceeding 20% and causing significant mor- bidity in survivors, sepsis is considered today a public health problem. Despite that mortality has been consist- ently associated with increasing organ dysfunction, the mechanisms by which sepsis causes multiple organ dysfunction are not well understood, and hence therapy remains reactive rather than preventive, and non- specific. Recent evidence has challenged the previous understanding of sepsis-induced organ dysfunction as being due to decreased blood flow-induced cell death by showing for example that acute kidney injury (AKI) occurs in the setting of normal or increased renal blood flow; and that it is characterized not by acute tubular necrosis or apoptosis, but rather by patchy, heterogeneous areas of tubular epithelial cell (TEC) oxidative stress and energy depletion. This paucity of apoptosis and necrosis, and the recognition that metabolic re- sponses to inflammatory injury may not only limit cell death in the acute phase but also, re-program energy regulatory pathways to determine future responses of epithelial cells, suggests that exploration of these mech- anisms represents potential therapeutic opportunities. Accordingly, the goal of this proposal is to determine the mechanisms by which the epithelial cell re-programs metabolism to adapt to inflammatory injury, and to under- stand the impact of these modifications on cell and organ function, and cell survival. The proposed research plan will be developed using cell culture and animal models in the frame of two specific aims. Aim 1 will deter- mine the role of AMPK in regulating the glycolytic and adaptive phases of the TEC response to sepsis. Aim 2 will dissect the role of mitophagy as an energy conserving response to limit TEC oxidative stress and cell death This research program will be framed in the context of a career development plan that will be described in the following pages and that is supported on three fundamental domains: Mentoring, Coursework and Research. The development of this program in the unique environment provided by the University of Pittsburgh, will allow the principal investigator (PI) to complete key training necessary to transition to independence focused on 1. The design and development of translational model systems to study sepsis induced organ dysfunction; 2. The quantification of epithelial cell energy regulatory pathways (AMPK), energy utilization and turnover, and mito- chondrial quality control processes during sepsis; and 3. Basic fluorescence and intravital microscopy tech- niques for the assessment of pathophysiologic processes in the living animal. These experiments will set the stage for future work to characterize the specific pathways linking energy regulation to organ dysfunction, and harness the possibility of manipulating these pathways to develop diagnostic, preventive and therapeutic strat- egies in a R01-funded project. Ultimately, the execution of this career development plan will uniquely position the PI as a future leader in sepsis research to improve the care of the critically ill patient. .