Mitochondrial Stress Signal Transduction from Organelle to Organism

项目摘要 神经内分泌和代谢应激源威胁细胞和有机体的完整性，导致 适应不良的细胞变化和疾病，除非通过核基因表达的适应性重塑来满足。 线粒体是这些适应的核心。最近的研究结果表明，线粒体参与了一个三- 一步细胞内信号转导系统，涉及传感，信号整合和转导到 它们在细胞核中调节人类基因组中的大多数基因。在这种情况下，线粒体是 作为细胞和有机体适应常见压力的决定因素。 这项建议的总体目标是确定线粒体的新机制， 细胞核信号传导导致基因表达重塑。为了实现这一目标，我的实验室使用 使用药物诱导的细胞器间连接体技术来操纵线粒体-线粒体和线粒体-核的相互作用， 肌肉细胞，再加上高分辨率的定量光学和电子显微镜的方法来跟踪 细胞器相互作用我们利用高通量功能测定、代谢组学和转录组学， 可视化和理解由此产生的核转录反应模式的压力。解开 线粒体网络组织和功能对线粒体信号传导的相对贡献， 利用独特的跨线粒体细胞和动物模型，以及靶向小分子 抗氧化剂和药理学试剂。候选信号通路将使用平行遗传学方法进行验证。 和生化实验。最有前途的途径将在后续研究中使用近- 实验性人类疾病模型的主要线粒体DNA缺陷，以验证我们在人类中的发现。 总之，这种结合的方法将调查特定的组成部分， 通讯系统及其与人类疾病的相关性。这项工作将建立物理基础， 线粒体基因表达调控，并作为进一步工作的基础，旨在规避 对应激源的不适应性细胞和有机体反应以及线粒体功能障碍。

PROJECT SUMMARY Neuroendocrine and metabolic stressors threaten cellular and organismal integrity, leading to maladaptive cellular changes and disease unless met by adaptive remodeling of nuclear gene expression. Mitochondria are central to these adaptations. Recent findings indicate that mitochondria participate in a three- step intracellular signal transduction system involving sensing, signal integration and transduction to the nucleus where they regulate the majority of genes within the human genome. In this way, mitochondria are a emerging as determinants of cellular and organismal adaptation to common stressors. The overall objective of this proposal is to define novel mechanisms of mitochondria-mitochondria and mitochondria-nuclear signaling leading to gene expression remodeling. To achieve this, my laboratory uses use drug-inducible inter-organellar linker technology to manipulate mito-mito and mito-nuclear interactions in muscle cells, coupled to high-resolution quantitative light and electron microscopy approaches to track organelle interactions. We exploit high-throughput functional assays, metabolomics, and transcriptomics to visualize and understand the resulting nuclear transcriptional responses patterns to stressors. To disentangle the relative contributions of mitochondrial network organization and functions to mitochondrial signaling, we leverage unique trans-mitochondrial cell and animal models, as well as mitochondria-targeted small molecule antioxidants and pharmacological agents. Candidate signaling pathways will be validated using parallel genetic and biochemical experiments. Most promising pathways will be extended in follow up studies using a near- experimental human disease model of primary mitochondrial DNA defects to validate our findings in humans. Together, this combined approach will investigate specific components of the mitochondria-nuclear communication system and their relevance to human disease. This work will establish the physical basis for gene expression regulation by mitochondria, and serve as the foundation for further work aiming to circumvent maldaptative cellular and organismal responses to stressors and mitochondrial dysfunction.