Dysregulation of Mitochondrial Dynamics in Sepsis

脓毒症线粒体动力学失调

• 批准号: 10371311
• 负责人: Bereketab Haileselassie
• 金额: $ 24.9万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10371311
• 关键词: Animal Model; Apoptosis Regulation Gene; Automobile Driving; Autophagosome; Biology; CRISPR/Cas technology; Cell Culture Techniques; Cell Line; Chemicals; Child; Clinical; Co-Immunoprecipitations; Confocal Microscopy; Critically ill children; Data; Development; Diagnostic; Dynamin; Enzymes; Failure; Financial Hardship; Fluorescence Resonance Energy Transfer; Functional disorder; Future; Goals; Healthcare; Hospital Costs; Knockout Mice; Knowledge; Link; Literature; MDM2 gene; Maintenance; Mediating; Mediator of activation protein; Methods; Mitochondria; Modeling; Multiple Organ Failure; Mus; Nuclear; Organ; Organ failure; Outcome; Oxidative Stress; Pathologic; Pathway interactions; Pattern; Peptides; Phase; Phosphorylation; Physicians; Play; Process; Protein Isoforms; Proteins; Repression; Role; Scientist; Sepsis; Sequence Homology; Site; Site-Directed Mutagenesis; Small Interfering RNA; Societies; Syndrome; System; TANK-binding kinase 1; TP53 gene; Technical Expertise; Testing; Training Programs; United States; Work; base; catalyst; conditional knockout; design; drug discovery; efficacy testing; experimental study; improved; inhibitor/antagonist; mitochondrial autophagy; mitochondrial dysfunction; mitochondrial membrane; mortality; neonate; novel; parkin gene/protein; peptidomimetics; pifithrin; preservation; prevent; recruit; septic; targeted treatment; therapeutic target; ubiquitin-protein ligase

Project Summary While recent literature suggests that p53, a regulator of apoptosis, is crucial in the development of sepsis- induced mitochondrial failure, the mechanistic underpinnings behind this finding are not clearly delineated. My preliminary studies have demonstrated that sepsis mediated mitochondrial localization of p53 propagates mitochondrial failure by interacting with dynamin-related protein 1 (Drp1) and promoting Drp1- fission 1 (Fis1) mediated mitochondrial fragmentation. Furthermore, increased mitochondrial localization of p53 in sepsis leads to an accumulation of damaged mitochondria by interacting with, and blocking, key mediators of mitophagy (process necessary for clearance of damaged mitochondria). Importantly, when p53 accumulation is blocked in a cell culture model of sepsis, Drp1 activation is decreased, excessive mitochondrial fission is abrogated and mitochondrial function is rescued. Taken together, my findings suggest that mitochondrial localization of p53 contributes significantly to mitochondrial failure by promoting excessive fission and dysfunctional mitophagy. However, the mechanism through which p53 interacts with key mediators of fission and mitophagy is not clearly understood. Accordingly, using cutting edge methods in chemical biology, this project will: 1) characterize the interaction site between p53 and key mediators of pathologic fission and mitophagy and 2) develop rationally designed peptides that abrogate the pathologic effects of p53 on the mitochondria. To achieve these goals proposed aims of this project are: AIM 1 (K99): Characterize the direct and indirect role of Drp1 on sepsis mediated p53 stabilization and mitochondrial localization. AIM 2 (R00): Determine the consequences of p53 localization patterns on sepsis induced mitophagy and characterize the interaction site between p53 and key mediators of mitophagy. , the AIM 3 (R00): Develop novel protein-protein inhibitors that interfere with pathologic interaction between p53 and mitochondria in sepsis. The proposed project is significant as it will reveal novel mechanistic pathways which contribute to end organ failure in sepsis by defining the link between excessive p53 activation and altered mitochondrial fission and mitophagy. Furthermore, this project aligns with my long-term goal to become an independent physician scientist, identifying therapeutic targets in mitochondrial pathways which abrogate sepsis-induced end organ failure in children. The training program in the K99-phase will further my technical skills and knowledge in chemical biology (aim 1). The proposed R00-phase will provide novel information regarding mitochondrial adaptors of p53 and develop rationally designed peptides that inhibit pathologic p53 - mitochondria interactions (aim 2&3).

项目摘要 虽然最近的文献表明，p53，一种细胞凋亡的调节因子，在脓毒症的发展中至关重要， 诱导的线粒体衰竭，这一发现背后的机制基础没有明确界定。我 初步研究表明脓毒症介导的p53的线粒体定位 与动力蛋白相关蛋白1（Drp 1）相互作用并促进Drp 1- fission 1（Fis 1），导致线粒体衰竭 介导的线粒体断裂。此外，脓毒症中p53的线粒体定位增加导致 通过与线粒体自噬的关键介质相互作用并阻断线粒体自噬， （清除受损线粒体所必需的过程）。重要的是，当p53积累被阻断时， 在脓毒症的细胞培养模型中，Drp 1活化降低，过度的线粒体分裂被消除， 线粒体功能得到了拯救。综上所述，我的发现表明p53的线粒体定位 通过促进过度分裂和功能失调的线粒体自噬而显著导致线粒体衰竭。 然而，p53与分裂和线粒体自噬的关键介质相互作用的机制尚不清楚。 明白因此，利用化学生物学的前沿方法，本项目将：1）表征 p53与病理性分裂和线粒体自噬关键介质相互作用位点; 2）合理发育 设计了消除p53对线粒体的病理作用的肽。实现这些目标 该项目的拟议目标是： 目的1（K99）：描述Drp 1在脓毒症介导的p53稳定中的直接和间接作用， 线粒体定位 目的2（R 00）：确定p53定位模式对脓毒症诱导的线粒体自噬的影响， 表征p53与线粒体自噬关键介质之间的相互作用位点。 得双曲余切值. 目的3（R 00）：开发新的蛋白质-蛋白质抑制剂，干扰p53和 败血症中的线粒体 该项目具有重要意义，因为它将揭示有助于终末器官的新机制途径。 通过定义过度p53激活和线粒体分裂改变之间的联系， 线粒体自噬此外，这个项目符合我的长期目标，成为一个独立的医生科学家， 确定线粒体途径中消除败血症诱导的终末器官衰竭的治疗靶点， 孩子K99阶段的培训计划将进一步提高我在化学生物学方面的技术技能和知识 (aim 1）。所提出的R 00期将提供关于p53和p54的线粒体衔接子的新信息。 开发合理设计的抑制病理性p53 -线粒体相互作用的肽（目标2&3）。