Mitochondrial Stress Signal Transduction from Organelle to Organism

项目总结 神经内分泌和代谢应激源威胁细胞和组织的完整性，导致 不适应的细胞变化和疾病，除非遇到核基因表达的适应性重塑。 线粒体是这些适应的中心。最近的发现表明，线粒体参与了一种三- STEP细胞内信号转导系统，涉及传感、信号整合和转导到 它们在核中调节人类基因组中的大多数基因。在这种情况下，线粒体是一种 成为细胞和机体对常见应激源适应的决定因素。 这项提案的总体目标是定义线粒体-线粒体和 线粒体-核信号导致基因表达重塑。为了实现这一点，我的实验室使用 利用药物诱导的细胞器间连接物技术操纵有丝分裂和有丝分裂-核相互作用 肌肉细胞，结合高分辨率定量光和电子显微镜方法来跟踪 细胞器相互作用。我们利用高通量功能分析、代谢组学和转录组学来 想象并理解对应激源产生的核转录反应模式。理清头绪 线粒体网络组织和功能对线粒体信号转导的相对贡献 利用独特的跨线粒体细胞和动物模型以及以线粒体为靶点的小分子 抗氧化剂和药理剂。候选信号通路将使用并行基因进行验证 和生化实验。最有希望的途径将在后续研究中扩展，使用近 实验人类疾病模型的初级线粒体DNA缺陷，以验证我们的发现在人类。 总而言之，这种结合的方法将研究线粒体的特定成分-核 通信系统及其与人类疾病的相关性。这项工作将为 线粒体对基因表达的调节，并为进一步研究如何规避 细胞和组织对应激源和线粒体功能障碍的异常反应。

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.