Role of ER-mitochondria contacts in dendritic Ca2+ homeostasis, synaptic integration and circuit function

内质网-线粒体接触在树突 Ca2 稳态、突触整合和电路功能中的作用

• 批准号: 9926321
• 负责人: FRANCK POLLEUX
• 金额: $ 56.02万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-05-15 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9926321
• 关键词: 3-Dimensional; Adolescent; Adult; Affinity; Alzheimer' s Disease; Apical; Axon; Biochemistry; Biogenesis; Biological; Brain; Cell Line; Cells; Collaborations; Communication; Complement; Complex; Coupled; Coupling; Cytoplasm; Data; Dendrites; Development; Endoplasmic Reticulum; Enterobacteria phage P1 Cre recombinase; Eukaryotic Cell; Farming environment; Fluorescence Resonance Energy Transfer; Glutamates; Goals; Head; Hippocampus (Brain); Homeostasis; Image; In Vitro; Individual; Ions; Knock-out; Knockout Mice; Link; Lipids; Maps; Mediating; Mitochondria; Modeling; Molecular; Morphology; Mus; Neurodegenerative Disorders; Neuroglia; Neurons; Organelles; Orthologous Gene; Parkinson Disease; Physiological; Physiology; Play; Property; Proteins; Regulation; Reporting; Role; Ryanodine; Saccharomycetales; Scanning Electron Microscopy; Science; Signal Transduction; Site; Slice; Smooth Endoplasmic Reticulum; Spatial Distribution; Structure; Supporting Cell; Synapses; Synaptic plasticity; Testing; Vertebral column; Yeasts; awake; base; calcium uniporter; cell type; gene replacement; hippocampal pyramidal neuron; in vivo; neuron development; neuronal cell body; novel; novel strategies; optogenetics; patch clamp; receptor; reconstruction; response; sensor; tool; two-photon; uptake; way finding

Organelle contacts are emerging as critical signaling platforms in metazoan cells. In non-neuronal cells, many of the important physiological functions played by mitochondria such as Ca2+ uptake and lipid biogenesis require a specialized structural and functional interface with the smooth endoplasmic reticulum (ER). Recent data from non-neuronal cells support a model whereby mitochondrial Ca2+ uptake can only occur upon Ryanodine and/or IP3 receptors-mediated Ca2+ release from the ER at sites of ER-mitochondria contacts, where Ca2+ transiently reaches high enough concentrations to open the mitochondrial calcium uniporter (MCU). Therefore, interfaces between organelles, such as ER and mitochondria, are emerging as critical platforms for many biological responses in eukaryotic cells. However, the function of ER-mitochondria coupling in developing and adult neurons is currently unknown despite recent ultrastructural evidence (including our own results) showing that numerous direct contacts between ER and mitochondria can be observed in dendrites in vivo. In addition, changes in the extent of ER-mitochondria contacts have been reported in various models of neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. However the pathophysiological impact of these changes in ER-mitochondria contacts is largely unknown. The goal of this proposal is to explore the role of ER-mitochondria interface in neuronal development, synaptic integration and circuit function. The major roadblock to study the function of ER-mitochondria coupling in any cell types including neurons is due to the absence of a molecular toolkit required to manipulate this organelle interface. We recently identified Pdzd8 as an ER protein playing a critical role in ER-mitochondria tethering (Hirabaryashi et al. Science 2017). We found that in cortical neurons, PDZD8 is required for Ca2+ uptake by mitochondria following synaptically-induced Ca2+-release from ER and thereby regulates cytoplasmic Ca2+ dynamics in dendrites. Our results identify PDZD8 as the first, critical ER- mitochondria tethering protein in metazoan cells and uncover a novel role for ER-mitochondria coupling in the regulation of dendritic Ca2+ dynamics in mammalian neurons. We hypothesize that PDZD8-dependent ER-mitochondria tethering plays critical roles in regulating cytoplasmic Ca2+ homeostasis in dendrites and might contribute to the formation of branch-specific Ca2+ ‘domains’ regulating synaptic integration and therefore in the dendritic properties underlying circuit function. Overall, our project will test, with unprecedented relevance, the role of a new biological interface, ER-mitochondria contacts, in dendritic Ca2+ dynamics, synaptic integration and circuit function in vivo.

细胞器接触正在成为后生动物细胞中的关键信号平台。在非神经细胞中， 线粒体发挥的许多重要生理功能，如钙摄取和脂质 生物发生需要一个特殊的结构和功能与光滑内质网的界面 (呃)。来自非神经细胞的最新数据支持一种模型，即线粒体钙摄取只能 发生于Ryanodine和/或IP3受体介导的内质网线粒体部位的钙释放 接触，其中钙离子瞬间达到足够高的浓度，以打开线粒体钙 单板机(MCU)。因此，细胞器之间的接口，如内质网和线粒体，是 在真核细胞中成为许多生物反应的关键平台。然而， 内质网-线粒体偶联在发育中和成体神经元中的功能目前尚不清楚 最近的超微结构证据(包括我们自己的结果)表明，许多直接接触 在体内的树突中可以观察到内质网和线粒体之间的联系。此外，程度的变化 在神经退行性疾病的各种模型中都有报道，例如 阿尔茨海默氏症和帕金森氏症。然而，这些变化对心脏的病理生理影响 内质网与线粒体的接触在很大程度上是未知的。 这项建议的目的是探索内质网-线粒体接口在神经元发育中的作用。 突触整合和回路功能。内质网线粒体功能研究的主要障碍 包括神经元在内的任何细胞类型的偶联都是由于缺乏所需的分子工具箱 操纵这个细胞器的界面。我们最近发现PDZD8是一种ER蛋白，在 ER-线粒体拴系(Hirabaryashi等人)。科学2017年)。我们发现，在皮质神经元中，PDZD8是 突触诱导内质网钙释放后线粒体摄取钙所需 调节树突细胞内钙离子的动态变化。我们的结果确定PDZD8是第一个关键的ER- 后生动物细胞线粒体拴系蛋白及其对内质网线粒体的新作用 哺乳动物神经元树突状钙动力学的偶联调控。我们假设 PDZD8依赖的内质网线粒体拴系在调节胞浆内钙稳态中的关键作用 在树突中，可能有助于形成树枝特异的钙调控突触结构域 集成，因此在树枝状特性基础上的电路功能。总的来说，我们的项目将 以前所未有的相关性测试一种新的生物界面--内质网-线粒体的作用 接触，在树突状钙动力学，突触整合和体内的电路功能。